ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 611 



Vascular System of Thysanura.* — Hermann Bar has studied in 

 particular the vascular system of Macliiloidea. The dorsal vessel in 

 these minute insects consists of a cephalic aorta, a heart, and a caudal 

 artery. The heart extends in the dorsal median line from the anterior 

 third of the meso-thorax to the tenth abdominal segment. It has 

 eleven paired dorsal ostia, and in the eighth and ninth al)dominal 

 segments a pair of ventral ostia, all with valves. Three bipartite 

 chamber-valves in the fourth, fifth, and sixth abdominal segments 

 hinder a back flow. A bipartite valve bounds the heart towards the 

 aorta, a posteriorly directed conical valve bounds the heart towards the 

 caudal artery. 



The cephalic aorta ends openly between the supra-oesophageal 

 ganglion, the commissures, and the oesophagus. The caudal artery 

 extends into the filum terminale, and must end openly. In the caudal 

 artery the blood flows Imckwards. 



The heart is kept in position by an incomplete dorsal septum, peri- 

 cardial tissue, and eleven alary muscles. The cephalic aorta is bound 

 by connective tissue to adjacent organs. The alary muscles are portions 

 of the dorso-ventral muscles. Histologically the dorsal vessel of 

 Machiloidea is like that of other Insects. There is a double blood stream 

 in this sense, that blood flows forwards in the heart but backwards in 

 the caudal artery. 



Indian Collembola.t — A. D. Imms gives an account of numerous 

 new forms of these primitive insects, the first, apparently, to be recorded 

 from the Indian Empire. He describes 4 genera and 27 species as new. 

 Three species, Ijelonging to as many genera, were already known. Out 

 of a total of 31 species, 5 are Palaearctic, and were obtained above the 

 limits of forest-growth in the Himalayas. The remaining species are 

 Oriental. 



Among the new forms discovered, the most remarkable is HeUro- 

 muricus cercifer g. et sp. n. It is unique among Collembola in possessing 

 a median cercus to the fifth abdominal segment. A new sub-family, 

 the Heteromuricinag, is proposed for its reception. Another interesting 

 form, Pseiuloeyphoderus annandalei g. et sp. n., is described from the 

 neighbourhood of Lake Chilka, where it occurs in Termites' nests. 



Desoria glacialis.J — J. A'allot 'reports the occurrence of immense 

 numbers of Desoria glacialis on the mer de glace at Chamonix. They 

 abounded over a stretch of about 20 by 2000 metres. In little pools of 

 water about a centimetre square there were about ten insects. In all 

 there were about forty millions, distributed over 4000 square metres, 

 which indicates an extraordinarily rapid multiplication of a somewhat 

 rare insect. 



* Jen. Zeitschr. Naturw., xlviii. (1912) pp. 1-92 (6 pis. and 5 figs.). 

 t Proc. Zool. Soc. London (1912) pp. 80-125 (7 pis. and 2 figs.). 



* Comptes Rendus, civ. (1912) pp. 184-5. 



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