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EDITORIAL NOTES. 



An important paper by Dr. D. Keilin has recently appeared in Parasitology, xi, 

 pp. 430-455, plates 22-25. It deals first with the life-history of the dipteron, 

 Melinda cogiiata Meigen, which the author found at Cambridge, living on the 

 animal of Helicella virgata, and goes on to review all observations hitherto made of 

 flies feeding on mollusks, either alive or dead. 



The fly did not attack other snails living with H. virgata. The larva when 

 full-grown pupates in the earth, and the imago emerges in fourteen days. The 

 parasitised snails were found from June to September, and the fly probably has 

 three generations a year, hibernating in the pupal stage. There are also some 

 hitherto unpublished observations by M. E. Seguy, of Rambouillet, who has found 

 the larvie of Aliisca domestica devouring live snails. 



Mr. y. D. Dean sends me a transcript of some interesting notes by Miss K. 

 Haddon, which appeared in the Proceedings of the Zoological Society for 1915, 

 relating to the preying of the glow-worm larva upon snails. This habit has been 

 already described by Newport and others, but their accounts do not tally. Miss 

 Haddon says : — " Newport describes the bite of the larva as causing great pain to 

 the snails, whereas Fabre, in a popular article on the subject, says that the snail 

 is anresthelised by the bite. My observations were carried out with a Zeiss 

 binocular, the larvje being placed with some moss in a shallow glass dish, and 



supplied with small snails The snail apparently is found quite by 



chance, and if hungry, the larva at once fastens on its prey. Bending its head 

 down, it cuts its way into the snail, which promptly withdraws into its shell, the 

 larva following. If left undisturbed, the larva feeds continuously, and is frequently 

 joined by others until the snail is finished. Wishing to see more clearly the 

 method of procedure, I supplied small slugs as food instead of snails. The larva 

 bit the slug on the visceral hump, but the slug with a twist of its body slipped 

 away, leaving a mass of mucus over the head of its enemy. ... In the next 

 attempt the attack was more fortunate, the larva striking right into the pulmonary 

 cavity of its victim, but either the food was not to its taste or else it was not 

 hungry, as it shortly let go, and the slug, which had previously been lethargic, 

 glided off apparently undisturbed. These observations show that, in these cases at 

 any rate, there was no anaesthetising. . . . Newport also observed some dark- 

 coloured fluid which flowed from the mouth of the larva at the time of its attack, 

 and apparently acted as a poison, for the snail was much more affected by the 

 bite of a larva than a mechanical injury, such as the piercing of a needle." 



Professor Boycott sends the following : — 



Among recent papers on the physiology of mollusca we may note L. B. Arey 

 and W. J. Crozier on the sensory responses of Chiton { /ourn. Exp. ZooL, xxix 

 (1919), no. 2 ; the reaction of Mya arenaria to light, by S. Hecht (fonrn. Gen. 

 Physiol., i (1919) 657, 667) ; G. v, Rijnberk on the mechanism of contraction in 

 the foot of Helix (Arch, neerl. de Physiol., iii (1919) 539) ; M. Copeland on the 

 importance of ciliary movement in the locomotion of Alectrion (Biol. Bull., 

 xxxvii (1919) no. 2) ; and a remarkable paper by H. N. Gould [Journ. Exp. ZooL, 

 xxix {1919) no. i) showing that the development of the male phase in Crepidula 

 is brought about by some unstable substance given off by females living near by ; 

 C. Dhere (Jcuru. de Physiol, et Path, gdn., xviii (1919) 221) deals at length with 

 hasmocyanin, the pigment of the blood, and [ib. 44) with helicorubin and helico- 

 fuscin, the pigments of the liver, of H. pomatia. 



