394 SUMMARY OF CURRENT RESEARCHES RELATING TO 



intergranular substance, nucleus and central apparatus. His view is that 

 the ectoplasm is represented by the membrane of the erythroblasts, that 

 the haemoglobin corresponds to the granula, that the central apparatus 

 and nucleus come to be more and more to one side. The nucleus is 

 eliminated and the blood-plates are the equivalents of the de-nucleated 

 erythrocytes. Numerous interesting figures of transitional stages are 

 given. 



Paneth's Cells.* — K. Miram has studied these cells in the small 

 intestine of the mouse. They are certainly also important in the young, 

 as Bloch maintained, for the elaboration of the milk, perhaps by secret- 

 ing a fat-digesting ferment. But they are also important throughout 

 life, in the mouse at least, for the absorption of fat, and perhaps also of 

 albuminoid material. 



Minute Structure of Choroid Plexus.f — W. Hworostuchin finds 

 evidence that the epithelium covering the choroid plexus of the lateral 

 ventricles and of the fourth ventricle contributes to the formation of the 

 cerebrospinal fluid. In the resting glandular cells of the plexus and in 

 the early stages of secretion there are mitochondria, which are probably 

 identical with Altmann's vegetative threads. In later secretion- stages 

 there are structures in the epithelial cells like Heidenhain's semilunar 

 corpuscles. 



Numerous nerve-fil)res form networks iu the plexus, both on the 

 blood-vessels and l)eneaththe plexus epithelium. From thesul)epithelial 

 network very fine filaments are given off, which end on the surface of the 

 epithelial cells. The epithelial cells of the plexus usually contain one 

 nucleus, but cells with two or three nuclei occur, probably as the result 

 of amitotic nuclear division. Among the elaborated products of the 

 gland-cells lecithin was demonstrated. 



Skin of Pig.J — E. Kranzle has made an intimate study of the 

 minute structure of the pig's skin. The division of the corium into 

 papillary, intermediary, and reticular strata is inadequate. The whole 

 surface of the corium shows well-developed papillary bodies. There 

 are numerous free sudorific glands not connected witli hair-follicles. 

 There are large seljaceous glands in the mucous membrane of the 

 lips, which show very fine hairs in connexion with them. The state- 

 ment of Flatten that the wild boar has no sudorific glands and the 

 English pig no sebaceous glands is erroneous. 



Fundus-glands of Pig's Stomach.§— G. Ulkan finds that the epi- 

 thelium of the pig's stomach is from the first a single layer. Il, is sharply 

 separated from the mesodermic tunica propria by a distinct membrana 

 propria. The fundus-glands arise from the epithelium, without help 

 from mesodermic elements. The primitive pits give rise to the definitive 

 pits and fundus-glands. 



* Arch. Mikr. Anafc., Ixxix. (1911, published 1912), pp. 105-13 (1 pL). 



t Arch. Mikr. Auat., Ixxvii. (1911) pp. 232-44 (1 pL). 



+ Arch. Mikr. Anat., xcvii. (1912) Heft 4, Abt. i., pp. 525-59 (2 pis. and 5 figs.). 



§ Anat. Anzeig., xli. (1912) pp. 78-80. 



