ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 455 



In addition, nuclei divided into four parts, where there was seen 

 to be gemmation, followed by constriction. 



After studying the lymphoid cells themselves, Kiikenthal passed 

 to their origin, function, and changes. They were found to arise 

 partly from connective-tissue-cells, and partly from cells of the body- 

 wall. The larger rounded cells are derived from cells which clothe 

 the ventral vessel and the nephridia : the smaller from the body- wall. 

 The brown or chloragogenous cells are derived from the lymphoid, 

 and owe their coloured contents to the dorsal vessel. After moving 

 about for some time they break up, and their contents form a blackish 

 detritus, which, as it is abundant in the region of the nephridia, may 

 be supposed to be passed to the exterior by those organs. 



After reviewing the work of those anatomists who have busied 

 themselves with annelids, the author comes to the conclusion that 

 what he has observed in Tuhifex obtains also in other ringed worms, 

 and especially in the Oligochseta. He has been able lately to make 

 some investigations on Limnodrilus ukedemianus, and Lumbricus ter- 

 restris ; in the former he has repeated point for point his observations 

 on Tuhifex. The study of Lumbricus was more difficult in consequence 

 of the opacity of the body-wall, but here also the lymphoid cells, 

 which were somewhat larger than in Tuhifex, exhibited similar phe- 

 nomena, and in addition to the tetraschistic mode of division 

 occasionally exhibited three, five, or six divisions. 



Tenacity of Life and Regeneration of Excised Parts in Lum- 

 bricus terrestris.* — Miss A. M. Fielde gives an account of experi- 

 ments on the tenacity of life, and describes the manner of regeneration 

 of excised parts in Lumbricus terrestris. She fui'ther reports having 

 found a completely regenerated brain, oesophageal collar, and sub- 

 oesophageal ganglion, all of normal size, and in normal site, in earth- 

 worms, which had fifty-eight days previously been decapitated at the 

 fifth segment. Forty days after decapitation the excised segments 

 had been regenerated, and five days after that the blood-vessels were 

 seen ramifying on the completely regenerated pharynx in a normal 

 manner, but no brain was found. 



Development of the Sexual Organs of Clepsine.t — Herr J. Nus- 

 baum has arrived at the following results from a study of the develop- 

 ment of the generative organs in Clepsine complanata. 



From the eight posterior endoderm-cells are formed by pro- 

 gressive multiplication from before backwards numerous " segment- 

 cells," which are arranged in pairs, one to each segment, on the 

 ventral side of the body. These give rise to seven pairs of spermato- 

 blast masses and two pairs of ovaries, the rest becoming dispersed 

 through the parenchyma of the body ; this condition, transitory in 

 Clepsine, recalls the permanent structural condition of many platy- 

 helminths. The oviducts and vasa deferentia are developed inde- 

 pendently and appear to be modified nephridia ; the short transverse 



* Proc. Acad. Nat. Sci. Philad., 1885, pp. 20-2. 

 t Zool Anzeig., viii. (1885) pp. 181-4. 



