430 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



finest, "brandies of the vascular system'. They are flattened, 

 fusiform bodies, mostly about 3-0V0 of an nica m length, and 

 are colorless. Lankester thinks that they are the nuclei of 

 the endothelial cells set free from the walls of the vessels, 

 while the granule in their centre represents the nucleolus. 



Leuckart discovered that a round worm (Spiroptera obtu- 

 sa), encysted in the meal-worm or larva of Tenebrio moli- 

 tor, completes its development in the digestive canal of the 

 mouse. More recently, M. Galeb has found that a small 

 round worm {Fllaria rhytipleurites) inhabiting the fatty body 

 of the common cockroach (Periplaneta orientalis) migrates 

 into the alimentary canal of the rat, the latter devouring 

 the cockroaches and setting free the immature FilariGB en- 

 cysted in the insect. 



A very full and philosophical account of the fresh-water 

 worm JVais, with reference to its mode of budding and self- 

 division, by Professor C. Semper, appears in a late number 

 of his Arbeiten, etc. 



A rotifer (JSFotommata icernecJtii) has been found by Bal- 

 biani to be at one period free, at another parasitic, in the 

 tubes ofVcaicheria, a fresh-water alga producing gall-like en- 

 largements. In the free state this rotifer is elongated, ver- 

 miform, and divided externally into distinct segments ; in the 

 parasitic state it is, when mature, dilated, sac-like, very con- 

 tractile, and without trace of segmentation, while the ovary 

 is enormously developed. Like other Rotifera, this species 

 lays two sorts of eggs, summer and winter ova. The latter 

 are produced in the spring, but are not laid until later, the 

 process of oviposition being delayed much longer than in that 

 of the summer eggs. The young Notommatas form in the 

 galls, and make their exit by openings which are made spon- 

 taneously at the summit of the adventive branches of the 

 Vaucheria. Other species of Notommata are known to re- 

 side parasitically in Volvox. 



Fritz Miiller, author of "Fur Darwin," some years ago an- 

 nounced that the Polyzoa, or corals, have a colonial nervous 

 system, which connects all the individuals of one colony to- 

 gether. M. Joliet, who has just been investio-atino- the sub- 

 ject, has come to the conclusion that Midler's nerves, gan- 

 glia, etc., are purely mythical, and that they arc simply lines 

 or branches running along the horny cells; and that the gan- 



