SCIENTIFIC NOTES. 127 



be the want of vegetable matter ; that is the case in many instances, 

 for the food is not enough for the maker and inquiline, but then we often 

 find two inquihnes infesting one small gall. This past week I have 

 examined a large polythalamous gall of Aiulriciis radiciH containing 

 sufficient vegetable matter to support many inquilines, if they would 

 live on it, but instead of feeding on the vegetable matter they had 

 consumed many of the gall makers, two, three, and in some cases four 

 inquilines had existed on a single gall larva. The common inquiline 

 of A . radicis is Sifnernns incrasHatns, and we find individuals of the species 

 very variable in size, and no wonder when the food (the larva of 

 A. radicis) is only enough to bring to maturity one full-sized inquiline, 

 two, three, or four manage to exist on it. 



On page 20 (an tea) the writer of the paragraph says : "How the mere 

 oviposition in the leaf or bud should cause such a different growth 

 when pierced by different species is a great mystery." The mere 

 oviposition in the leaf or bud does not make any difference to the leaf 

 or bud. If the egg is not hatched no distortion of the leaf or bud takes 

 place ; the larva is the prime mover of the growth and as long as the 

 larva is active the usual gall growth continues. Should the larva die or 

 get injured from any cause before the growth of the gall is completed, 

 the growth activity ceases, and sometimes, but very rarely, while the 

 larva is active. P. Cameron, in Ilai/ Soc. Vol., iv., p. 10, says: " Asa 

 rule they (the inqiiilines) kill the larva of the gall maker." On p. 21 

 he says : " In C;iniiiidac the birth of the larva is synchronous with the 

 formation of the gall — until the larva is born and commences feeding 

 there is no gall-formation." — G. C. Bignell, F.E.8., The Ferns, 

 Home Park Eoad, Saltash, Cornwall. Janitarij 26^/;, 1901. 



The cry of Acherontia atropos. — Material being available this year, 

 I thought it well to investigate this subject for myself, one reason being 

 that I had quite forgotten all about Moseley's paper in Nature, though 

 I must have read it. Nature, at the date of its appearance, being part 

 of my regular reading. This had, however, the advantage of leaving 

 me quite unbiassed, and led me to a rather extended examination of 

 the anatomy of A. atropoa. My specimens all had to come by post, 

 and so did not cry so freely as might be desired, and gave an undue 

 importance to anatomy over experiment. It was plain that the noise 

 appeared to come from, or from near, the head ; the friction of pro- 

 boscis and palpi had nothing to do with it, as they could be held apart 

 without affecting it. The only movement associated with the noise 

 was one of the under surface of the base of the abdomen ; a similar 

 movement as an ordinary respiratory one occurred, without any noise 

 being produced. I made search, however, amongst the air-sacs and 

 ililated trachese of the thorax and abdomen without finding anything 

 to produce a sound. I then examined the spiracles. These have a 

 very beautiful double valve of lace-like structure as an outward pro- 

 tection, but all seemed to be nearly alike, and I coiild find nothing to 

 suggest the pro-thoracic spiracle as a squeaking organ. Nor could I 

 find anywhere any stridulating surface. The corrugations of the pro- 

 boscis and palpi are rounded, and do not touch each other, confirming 

 the experimental proof that there is no stridulation here. A strained 

 extension of the proboscis did not stop the sound, but distinctly 

 altered the note, rendering it certain that the source of the sound was 

 affected by this altered position. The opposed edges of the two halves 



