ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 433 



The species of Diaptomus show monocyclic reproduction, the others 

 show alternation of reproductive periods. While D. laciniatus shows a 

 continuous development and winters in a differentiated stage, the other 

 species (D. denticornis) probably winters in an embryonic stage. 



The females seem to be more uniformly distributed than the males 

 — which are more sensitive to changes in light and heat, and alter their 

 vertical distribution more markedly. 



Lateral Hermaphroditism in Palinurus frontalis.* — O. Burger 

 describes an interesting asymmetrical specimen of this lobster, which in 

 its appendages and other hard parts was distinctly female-like on the 

 loft side and male-like on the right. 



Annulata. 



Regeneration in EnchytraeidaB.f — J. Nusbaum has studied regenera- 

 tion-processes in Fridericia ratzelii Etsen and Enchytrseus buchholzii 

 Vejd. Some of the processes, e.g. formation of the proctodeum, follow 

 the ontogenetic mode ; others, e.g. the ectodermal renewal of the muscu- 

 lature, especially the circular musculature, follow a simplified, more 

 primitive plan. 



Circulation in Lumbricus.J — J. B. Johnston and Sarah W. Johnsou 

 find that the circulation in each segment behind the hearts of the earth- 

 worm is as follows : — the branches of the lateral neurals and parietals 

 collect blood from the body-wall ; the parietals take blood to the dorsal 

 from the sub-neural body-wall and nephridia ; the dorso-intestinals give 

 blood to the dorsal from the intestine ; all of this blood goes forward in 

 the dorsal to the hearts ; through them nearly all of it is given to the 

 ventral vessel, which sends it to the intestine through the ventro- 

 intestinals and to the body-wall through the ventro-tegumentaries. 

 The head-region is supplied with blood by the dorsal and ventral 

 vessels, while the neurals and laterals carry blood from it. The dorsal 

 and ventral vessels carry mixed blood : the neurals carry oxygenated 

 blood only ; the laterals carry backward mixed blood. 



Two new Earthworms.§ — F. E. Beddard describes Octochsetm 

 beatrlx sp. n. and Benhamia tanganyikse sp. n., Acanthodriloid earth- 

 worms of the family Megascolicidae. 



Peritoneal Elements of Phascolosoma vulgare.|| — M. A. Herubel 

 describes the chloragogen elements and the ciliated urns in the ascending 

 coil of the intestine of this worm. He discusses the relation of the 

 urns to the chloragogen cells which they always have as their neigh- 

 bours ; and he also points out that there are never urns apart from 

 membranous connective tissue. The urns rapidly remove injurious solid 

 bodies from the cavity of the gut ; the chloragogen cells act more slowly 

 as " microphagous " peritoneal cells. The urns seem to digest, as far as 

 possible, the bodies which they capture. 



* Zeitschr. wiss. Zool., Ixxi. (1902) pp. 702-7 (4 figs.). 



t Biol. Centralbl.. xxii. (1902) pp. 292-8. 



t Amer. Nat., xxxvi. (1902) pp. 317-28 (3 figs.). 



§ Ann. Nat. Hist., ix. (1902) pp. 456-63. 



|| Bull. Soc. Zool. France, xxvii. (1902) pp. 105-14 (4 figs.). 



