230 SUMMARY OF CURRENT RESEARCHES RELATING TO 



inner part of the lower maxillary palp. These organs are probably useful 

 in detecting variations in the conditions of the atmosphere. 



Mechanism of Respiration in Myriopods.* — In the Myriopods there 

 are no special movements in the respiratory apparatus, able to produce an 

 indraught and outdraught of air, as in insects. M. J. Chalande has made 

 experiments on some of the Myriopods, and comes to the conclusion that 

 inspiration and expiration of air are due to contraction and expansion of the 

 dorsal vessel. The blood passing along the sinuses in the body bathes 

 the tracheae, and accentuates at each contraction the curve of the tracheae ; 

 thus there is an alternating increase and decrease of the total capacity of 

 the respiratory apparatus, during repose. This is increased during motion 

 by the action of the muscles of the legs, and by the movement of the 

 alimentary tract during digestion. Moreover a lowering of the tempera- 

 ture acts on respiration by a diminution in the contractions of the dorsal 

 vessel. 



Structure of Spinning-glands of Geophilidae.f — Dr. E. Tomosvary 

 finds that the spinning-glands of GeopMlushavG the ordinary constitution of 

 arthropod dermal glands — gland, duct, and tunica propria of the gland ; 

 each compound gland ordinarily opens by a special compound gland ; and 

 these are themselves foimd between the space formed by the lateral fold of 

 the pleura and between the muscles of the last body-segment ; they are 

 spherical or pyriform in shape, and consist of a number of tubular simple 

 glands of the value of cells ; in each a cell-membrane, granular cell-contents, 

 and a cell-nucleus are to be made out. The efferent duct is proportionately 

 long and rather wide, and has a pretty thick hyaline wall ; the tunica 

 propria is a fine hyaline membrane which may be regarded as the inner 

 membrane of the matrix of the chitinous layer. It may be concluded that 

 the spinning-glands are compound dorsal glands which are derived from the 

 ectoderm, and have undergone invagination. They are very like the poison- 

 glands of Chilopods, but their spinning function is inferred from the fact 

 that it is their fluid secretion — which hardens on exposure to air — that 

 forms the body which cements together the ova and spermatozoa. 



Phosphorescence of Geophilus.| — M. Mace has studied the phospho- 

 rescence of a species which appears to be Geophilus simplex ; the phenomenon 

 seemed to him to be due to a colourless liquid which is very slightly viscous 

 and dries rapidly ; it is not excreted from the anal orifice, but from the 

 whole of the ventral surface of the body ; the light is a little less strong 

 than that of Lampyris and seems to be of a green colour. At the com- 

 mencement of the observation the whole of the back was phosphorescent, 

 but at the sides were the two lines of greatest intensity ; after a short time 

 the light began to fade from the back, and then from the side ; for some 

 minutes a longitudinal row of bright dots shone at the sides. These, so far 

 as the author could judge from the darkness in which the observations were 

 necessarily carried on, were situated near the stigmatic orifices. 



The explanation of Dubois does not seem to apply to these Myriopods ; 

 like certain Chaetopteri and Polynoids described by Panceri, the light seems 

 to be due to a mucus secreted by the skin, and transverse sections show 

 that, in the region of the stigmata, there are masses of large hypodermic 

 cells which are probably the secreting agents. 



* Comptes Rendus, civ. (1887) pp. 126-7. 



t Mathemat. u. Naturwiss. Bcrichte aus Ungarii, ii. (1884) pp. 441-C (1 pi.). 



X Comptes Rendus, ciii. (1886) pp. 1273-4. 



