130 ON TRANSPARENT INJECTED PREPARATIONS. 



be seen at all except by those who have the power^ which but 

 few possess, of making injections for themselves. 



Skm. — The preparations of the skin are not numerous. 

 They are entirely from the human subject, and present sec- 

 tions from the head, showing the hair-follicles. These might 

 be increased with advantage. Examples of the perspiratory 

 glands, with the capillaries of the true skin, and of follicles 

 with Demodex in situ, would be interesting, as supplying 

 objects not always easily obtainable at present. 



Tongue. — ^These preparations consist of several sections 

 from the human tongue, and that of the rabbit, cat, and 

 mouse. They are interesting as exhibiting the lingual gland 

 and the constitution of the blood-vessels in this organ. 



Organs of digestion. — In this series we have no prepara- 

 tions from the human body. There are, however, very in- 

 structive sections from the stomach of the mouse and rabbit, 

 and also preparations exhibiting the structure of the mucous 

 membrane in the large and small intestines of the guinea-pig, 

 the rat, the mouse, and the cat. We have seen but one pre- 

 paration of the liver, and that from the rabbit. There is also 

 mentioned in the catalogue the spleen of the rat, exhibiting 

 a longitudinal vertical section, with the vessels of the Mal- 

 pighian bodies and of the pulp. 



Urinary organs. — These all come out very beautifully. In 

 the human kidney the relation of the glomeruli to their cap- 

 sules is seen. In the kidney of the rabbit, the rat, the mouse, 

 and the snake, very interesting varieties of structure are seen. 



Organs of respiration. — The lungs afford a very fine oppor- 

 tunity to the maker of these preparations, and in the perfec- 

 tion of the injection of the vascular network in the air-cells 

 we have seen no better illustration than these. It is probable 

 that a larger stock of these than the two mentioned in the 

 catalogue — the rabbit and the mouse — may be in the posses- 

 sion of the preparer, and we should think a series of these 

 would be highly interesting to the general or professional 

 student. 



Reproductive organs. — Of these there is also a deficiency in 

 the catalogue. The only two mentioned are the human 

 placenta and the corpus luteum of the pig. A large series of 

 these would be highly instructive if prepared as carefully as 

 the parts we have already commented on. 



Development of the organs. — The parts of animals represent- 

 ing the states of organs at different periods in their develop- 

 mental history are always most difficult to procure. In these 

 preparations different portions of the embryo of the sheep, the 

 cat, the rabbit, and the rat, are exhibited. In onlv one in- 



