ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 879 



were twice met with, having a small stolon coveretl with buds ; but 

 this stolon fliffered essentially from that of the sexual form. 



In addition to two pairs of very strong nerves running towards 

 the anterior and posterior apertures of the body, the ganglion gives 

 rise to nerves that terminate in the cells of the exterior and interior 

 epithelium, besides others to diiferent portions of the body. The 

 termination of these nerves is excessively varied, giving rise to the 

 sujiposition that the specialization of the organs of sense here reaches 

 a very high degree. 



Among the corpuscles of the general cavity of the body two 

 principal types predominate, which the author calls nutritive or 

 plastic corpuscles and formative corpuscles. The blood-corpuscles 

 present only a slight modification of the former. The plastic cor- 

 puscles are believed to originate from the cells of the alimentary 

 canal, and by their aid restoration of injured parts takes place. The 

 formative corpuscles may in some instances reconstruct or replace 

 the nerve terminations. The corj^uscles that give rise to buds differ 

 by their very rapid movement and by the presence in their interior of 

 small particles of crystalline form. 



Closure of the Cyclostomatous Bryozoa.*— A. W. Waters, re- 

 ferring to the want of characters for classifying the Cyclostomata, 

 points out that the ovicells ought to be very carefully examined, as 

 there are more points of importance than have so far been used ; the 

 connecting pores are also, he considers, comparable with the rosette- 

 plates of the Chilostomata, and give by their position useful 

 characters. Stress must also be laid on the size of the zooecial tube, 

 which seems to be constant in each species, whilst the position of its 

 closure constitutes a hitherto neglected character which may possibly 

 be of great use. The most usual position for the calcareous plate 

 which closes the tube would seem to be about the point where this 

 tube rises free from the zoarium. Sometimes the plate has one 

 opening, in other species there are a number of openings, or there 

 may be only very minute perforations, and it is apparently sometimes 

 quite closed. Two closures quite close together are sometimes 

 present instead of one. Its function, the author considers, may be 

 to keep the zocecium from being choked up by sediment during its 

 polypideless condition. 



Arthropoda. 



o. Insecta. 



Movements of the Heart of Insects during Metamorphosis.f — 

 J, Kiinckel, attracted to the question of cardiac movements in insects 

 during their metamorphosis, has especially studied the Syrphidae, 

 where the length of the period of their development and the large size 

 of the animals offer very favourable conditions for investigation. 

 For four days after the larvse have lost the power of movement the 

 heart may be still seen to be beating very regularly ; the phenomenon 



* .Journ. I.inn. Soc. Load. (Zool.), xvii. (1884) pp. 400-4 (1 pi.), 

 t Complea Bendus, xcix. (1881) pp. 151-;i 



