ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 11 



Mucous Membrane of Human Alimentary Canal.* — J. E. Schmidt 

 finds that the cells of Paneth appear first in the gut of the human foetus 

 in the seventh month, and in the new-born child have attained their 

 full development. Normally they are found in the whole of the small 

 intestine, frequently in the vermiform appendix ; practically absent in 

 the healthy rectum, they occur here pathologically in polypi, and in the 

 border of carcinoma. There is a specific relation to the digestion of 

 vegetable matter. Goblet-cells are developed in the third month ; their 

 number increases gradually ; towards the end of foetal life they become 

 so abundant that in the new-born child the whole rectum and vermi- 

 form appendix are covered by an almost continuous layer of goblet-cells 

 and mucus ; the lower small intestine also shows goblet-cells in 

 abundance. In the gut epithelium of the human foetus peculiar cell 

 inclusions occur in the middle of pregnancy, which, on further growth, 

 have the form and reactions of meconium corpuscles. These are emptied 

 into the gut, so that in the new-born child there are no epithelial 

 inclusions. The formation of these corpuscles in the gut is con- 

 temporaneous with the beginning of swallowing movements and of the 

 taking up of amniotic fluid in the gut canal. In the dog the same 

 process begins only shortly before birth and ends during the first 

 fourteen days of extra-uterine life, so that here the development of the 

 whole series in the gut epithelia can best be followed. 



Structure and Development of Integument.f — E. Retterer con- 

 tinues his account of observations on this subject. The present paper 

 deals with the histogenesis of elastic fibrillae ; fundamental substances 

 — e.g. cement, plasma, mucin ; covering epithelium and epidermis ; the 

 origin of the external tegument, and the union of epidermis and the 

 dermis ; closed follicles of the original epithelium. Some of his general 

 conclusions from the whole research may be quoted. The covering 

 epithelium of the external tegument develops both to the outer and 

 inner sides. The cells of the middle and deep layers proliferate to 

 replace those that desquamate, and to produce cellular generations which 

 will be transformed into connective elements. A reticulated tissue is 

 formed whose cellular individualities each contain, besides a nucleus, a 

 cytoplasm differentiated first into laminse and anastomosed chromato- 

 phile filaments, and secondly into a hyaloplasma in the meshes of the 

 chromatophile reticulum. The development of reticulated tissue is the 

 same in the region of the papillae and of the follicles. After this web 

 is formed, the elements dissociate themselves from the dermis, the fibres 

 become gelatinous, and the cellular remains are transformed into 

 leucocytes. 



Structure and Histogenesis of Bone4 — Ed. Retterer gives an 

 exhaustive account of the minute structure and development of bony 

 tissue, with special reference to Mammals and Teleosts. 



Structure of Tooth Canaliculi.§— L. Fleischmann has studied these 

 in man, monkey, and horse. He has made out the following points. 



* Arch. Mikr. Anat., lxvi. (1905) pp. 12-40 (1 pi.). 



t Journ. l'Anat. et Phys., xl. (1904) pp. 493-535 2 pis.). 



X Op. cit., xli. (1905) pp. 561-640 (12 figs.). 



§ Arch. Mikr. Anat., lxvi. (1905) pp. 501-24 (1 pi.). 



