figures 33 and 34 were drawn in accordance with this belief; but during a visit recently paid to England by my old friend Professor Graf Solms-Laubach, he informed me that such is not the case. As soon as the leaves of Lomatophloios are developed, instead of ascending, they bend downwards, overlapping and hiding the leaf-cushion from view. I found from Count Solms that Lomatophloios is much more common in Germany than in England; consequently our friends across the water are more familiar with its aspect than Englishmen are. Nevertheless, when thus enlightened by my friend, I found fragments in my collection which made clear to me that I had fallen into an error. we It follows from this fact that several of my figures in Part XIX illustrating the structure of these leaves are simply turned upside down, and require to be reversed. This is the case with fig. 13 on Plate 2, and with figs. 33, 34, 36, and 37 on Plate 4. Thus drawn, these figures misrepresent the relative positions of three important internal structures, viz., the Leaf-trace, the bifurcating Parichnos, and what has received the name of the Ligule. Our attention was, I believe, first called to this latter organ by the late Professor Sturr, of Vienna, but it has subsequently been further commented on by Professor Bertrand, of Lille, in conjunction with M. Hovelacque, of Paris. It is now clear that the Leaf-trace is the more central organ, having the so-called Ligule above and the double Parichnos below it. Apart from their inversion, my figures of these organs are absolutely accurate. Fig. 13, in Plate 2, though belonging to a true Lepidodendron, represents the Parichnos g, as resting upon the Leaftrace c'. In thus arranging these two organs in a Lepidodendron, I was misled by the specimen represented in Plate 4, fig. 36. All these errors, arising from a common misunderstanding, are now corrected. Of course it follows that all such terms as upper and lower, used in the text describing the above-named five figures, must be severally reversed. On p. 9 of my memoir I criticised the application by MM. Bertrand and Hovelacque of the name Ligule to the organ to which they had assigned it, because they thus identified the organ as being the homologue of the appendage so named in the living Selaginella. In the latter case the Ligule springs from the upper surface of the leaf, whereas the mistaken impression under which I laboured, led me to believe that in the fossil forms it sprang from the under side. Of course, any argument based upon the latter supposed fact now falls to the ground. At the same time, like Solms-Laubach, I should be cautious in accepting this supposed homology as proven. Nevertheless, some curious points of resemblance between the primeval and the recent types make this identity far from impossible.* It appears to me that much uncertainty exists amongst Palæobotanists re VII. "Report on some of the Changes produced on Liver Cells by the Action of some Organic and Inorganic Compounds.” By T. LAUDER BRUNTON, M.D., F.R.S., and S. DELÉPINE, M.B. Received March 14, 1894. We have, on a former occasion, given an account of the scope of the investigation, and of the methods used, of some preliminary observations* which we have found it necessary to make. Briefly speaking, our object was to ascertain the action of drugs on the cells of the liver and to connect, if possible, the changes in the cells with the physiological action of the drugs and their chemical structure. Certain drugs were selected by one of us (Brunton) as being most suitable for this investigation. These drugs were the following: We have recorded the various appearances which we have observed as the result of the purely physiological stimulation of the liver produced by the ingestion and digestion of a meal, and have noticed that the most important changes indicating various states of activity were :— 1. The size of the cells. 2. The distinctness of the mitoma and of the cellular cleavage. specting the structures that distinguish Lepidodendron from Lepidophloios. Some trust to the several forms of the sections of the leaves, leaf-scars and leafcushions; others to the upward or downward directions taken by the elongated portions of the leaves. In fact the question demands a more critical and conclusive investigation than it has yet received.-Note, April 19, 1894. *Roy. Soc. Proc.,' Oct. 22, 1891, vol. 50, p. 209, and Paper placed in the Archives. 3. The size and arrangement of the meshes of the mitoma of the cells. 4. The size of the biliary canaliculi. 5. The amount and distribution of the glycogen in the cells and in the lobules of the organ. 6. The amount and distribution of granules giving the reaction characteristic of inorganic ferric salts.* We also recorded changes affecting other parts, but we need not consider them for the present. We will now give an account of the appearances produced in the liver soon after the administration of the compounds mentioned above, either subcutaneously, by the rectum, or by the mouth (the latter in only two cases) : 1. To rabbits that had taken a moderate amount of food (50 grams of carrots from 7 to 9 hrs. before death-in two cases only the time was less than 7 hrs.); 2. To rabbits that had not been fed for at least 24 hrs. before death. To estimate the changes produced, the organs of animals to which drugs had been administered were compared in each case with those of animals in the same stage of digestion, but to which no drug had been administered. Thus, when we say that a drug causes an enlargement of the meshes of the mitoma, or renders them more distinct or indistinct, or causes an accumulation of iron, we always mean that the state in which the cells would have been at the same stage of digestion has been modified in the direction indicated. As the measurements of cells and parts of cells necessitate the careful drawing of a large number of cells with the camera lucida, the report, in its final shape, cannot yet be given, but, as all the appearauces observed have been taken note of during the progress of the investigation, we are in position to give an idea of the results which have so far been obtained, but which we are not yet able to express in numbers, and compare as accurately as we hope to do when all our measurements are completed. Action of Pilocarpine on a Fasting Liver. A.-Last food given 25 hrs. before death. Pilocarpine nitrate (grain = gram 0.042, dissolved in 10 c.c. of water) was injected into the rectum 1 hr. and 28 mins. before death. * Loc. cit., and also “Contribution to the Study of the Vertebrate Liver," 'Roy. Soc. Proc.,' Nov. 20, 1890, vol. 49, p. 64; "On the Normal Storage of Iron in the Liver," Practitioner,' vol. 45, p. 94. B.-There were very few psorosperms in the liver, which was of small size. Cells small, or of medium size. Outlines of the cells and the mitoma much clearer than normal. Meshes of the mitoma pretty large; some grouped round the lateral bile canaliculi. Main and lateral bile canaliculi very distinct and very large. Glycogen reaction normal, i.e., doubtful and diffuse. Only slight traces of sugar could be obtained in 24 hrs. after death. Iron reaction less marked than normal. C.-The state of the mitoma of the cells, and the amount of iron indicate secretory activity. This may be taken as a type of liver in a state of secretory activity. Action of Pilocarpine on a Fasting Liver. A.-Last food given about 26 hrs. before death, the food not eaten being removed 17 hrs. before death. (This is an exception to the rule generally followed.) Subcutaneous injection of grain of pilocarpine (a little more than gram 0.03) was given 1 hr. 30 mins. before death. B.-Liver apparently healthy. Cells large and swollen looking. Outline of the cells and the cellular mitoma extremely distinct. Meshes of the mitoma very large. Bile canaliculi large and distinct. C.-These changes correspond to those observed in an active liver, and may be taken to indicate secretory activity. Action of Pilocarpine on a Fed Liver. A.-Last food given 7 hrs. before death. Death blow 2 hrs. 43 mins. after a first subcutaneous injection of grain (gram 0·042) of pilocarpine (a second injection of the same quantity having been given 38 mins. before death). B.-Liver moderately diseased, containing a few large psorospermic masses, and being somewhat above the average size. Cells generally large but variable in size. Outlines of cells and the mitoma even more distinct than normal. Meshes of the mitoma large, specially round the nuclei. Bile canaliculi indistinct. Glycogen reaction about normal, slightly diminished. Iron reaction much diminished, both in the diffuse and in the granular form. C.-The changes produced in the fed liver correspond closely with those observed in the fasting organ, and may be taken as typical of secretory activity. Action of Toluene on a Fasting Liver. A.-Last meal 31 hrs. before death. Rectal injection of 1 gram (15.5 grains) of toluene suspended in 10 c.c. of thin mucilage, 56 mins. before death. B.-Liver of moderate size, with pretty abundant psorospermic lesions. Cells small and medium sized. Outline and mitoma clear, much clearer than normal. A few large meshes, specially grouped round the nucleus. Bile canaliculi not generally distinct, when distinct very narrow. Glycogen reaction distinct round the hepatic vein, and therefore increased. Sugar formed in 24 hrs. post mort., much more abundant than normal. Iron reaction almost absent, and therefore less than normal. C. The action resembles somewhat that of pilocarpine, but differs from it on account of the increase of glycogen. Action of Toluene on the Fasting Liver. A.-Last meal 20 hrs. before death. Subcutaneous injection of about 0·06 gram (i.e., = about 0·9 grain) of pure toluene 4 hrs. 45 mins. before death. B.-Liver apparently not diseased. Cells pretty large. Outline of cells and mitoma more distinct than normal. Meshes of mitoma a little larger than normal. Bile canaliculi very distinct. Blood capillaries rather congested. C.-There is stimulation of the cells resembling, to a certain extent, that produced by pilocarpine, but much less marked. |