578 SUMMARY OF CURRENT RESEARCHES RELATING TO 



" supra-pericarclial " bodies. The post-branchial bodies of amphibians 

 are directly homologous with those of reptiles, but only serially homo- 

 logous with those of birds and mammals. 



b. Histology. 



Chromidial Apparatus of Actively Functioning- Cells.* — R. Gold- 

 schmidt comes to the following conclusions : (1) Every animal cell is 

 essentially bi-nucleate ; it contains a somatic and a propagative nucleus. 

 The first has to do with somatic functions, metabolism and movement,, 

 and may be called the metabolic or kinetic nucleus. The other contains 

 especially the hereditary substances, and has the power of producing 

 another metabolic nucleus. (2) The two kinds of nucleus are usually 

 combined in an amphinucleus. The separation occurs in varied degrees. 

 A complete separation of the two is rare ; most frequently there is a 

 separation into a nucleus predominantly propagative, but still mixed, the 

 cell-nucleus in the ordinary sense, and the main mass of the somatic 

 nucleus, to wit, the chromidial apparatus. (3) Complete separation of 

 the two nuclei is seen in some Protozoa, and during the oogenesis and 

 spermatogenesis of Metazoa. (4) In tissue-cells the separation may not 

 be noticeable, as in most cells which are not functioning actively, as 

 also in mature egg-cells. But two kinds of chromatin, idio-chromatin 

 and tropho-chromatin, may be detected. In other cases the elements of 

 the somatic nucleus form a chromidial apparatus in the plasma (cyto- 

 microsomes, mitochondria, chondromites, accessory nucleus, etc., etc.). 

 (5) Cells with only a propagative nucleus (e.g. gametes of Protozoa), 

 or with only a somatic nucleus (e.g. residual body of Gregarines, some 

 muscle cells), may also occur. 



Ergastoplasm and Mitochondria.! — P. Bouin has based a number 

 of general conclusions on a study of the seminal cells in Scoloj)endra 

 cingidata. He maintains that the cytoplasmic differentiations described 

 in the male and female sex-cells of various organisms, under the names 

 pseudo-chromosomes, central capsules, spicules, chrondriomites, mito- 

 chondria, and ergastoplasmic filaments, are homologous formations. To 

 these, too, are related the " batonnets " of the accessory nucleus, the 

 archoplasmic and archiplasmic loops, and the kinoplasmic filaments. 



Intra-Epithelial Glands.; — M. Nussbaum directs attention to 

 Citelli's§ description of intra-epithelial glands. But these were first 

 described by Nussbaum (1883) in the gullet of the slow-worm. 



G. Seiffert || has, at Nussbaum's request, studied the glands in the 

 ureter of the horse. There are no unbranched simple glands in the 

 epithelium, such as Hamburger IT reported. The glands in the upper 

 third of the ureter are branched tubular glands. 



Secretory Function of Nucleus of Hepatic Cells.** — T. Browicz 

 brings forward additional evidence in support of his previously stated 



* Zool. Jahrb., xxi. (1904) pp. 41-140 (6 pis. and 16 figs.). 



t Arch. Zool. Exp., iii. (1905) pp. 99-132 (2 pis.). 



\ Anat. Anzeig., xxvii. (1905) pp. 121-2. 



§ Op. cit., xxvi. (1905) p. 480. || Op. cit, xxvii. (1905) pp. 122-5 (3 figs.). 



1 Arch. f. Mikr. Aiiat, 1880, No. 17. 



•* Bull. Internat. Acad. Sci. Cracovie, 1905, No. 3. pp. 250-3 (1 pi.). 



