The Zoologist — March, 18C7. 645 



Mr. G. S. Saunders exhibited a nest formed by social caterpillars among the leaves 

 of a Brazilian tree, a species of Zeyhera; it was about a foot in length, and formed a 

 compact web between two small branches. The nest was collected in 1866 by Senor 

 J. C. de Mello, at Campinas, Province of S. Paulo, and by him sent to Mr. Daniel 

 Hanbury. 



Mr. Wormald exhibited a collection of Insects sent from Shanghai by Mr. William 

 Pryer, amongst which was a single specimen of a wild Bombyx, having some 

 resemblance to B. Huttoni. 



Dr. Wallace exhibited an English cocoon of Bombyx Yamaraai, one of two reared 

 in 1866, at York, by Mr. Dossor. 



Dr. Wallace also exhibited numerous specimens of the cocoon and imago of 

 Bombyx Cynthia, and the silk thereof. One was a double cocoon, the joint work of 

 two larva?. Another cocoon, formed in 1865, and which in due course ought to hare 

 produced a moth in 1866, contained a still living pupa, which would probably hatch in 

 1867. He mentioned that though the moths were greedily eaten by fowls and other 

 birds, the larvee, though not hairy, were rejected; and that when Ailanthus leaves were 

 sot procurable the larvae had been found by Captain Hutton to thrive on honeysuckle. 

 The moths of B.Cynthia were subject to considerable variation in size and coloration. 

 He had invariably found that at the commencement of the hatching out of a brood the 

 males greatly outnumbered the females, whilst at the end the reverse was the case : he 

 argued that in proportion as the individual was finer the time required for its meta- 

 morphosis was longer; hence in general the female, which was the larger and heavier 

 insect, was preceded by the male, which was smaller and had less to mature. He 

 thought Bombyx Guerinii and B. Ricini were probably only varieties or local forms of 

 B. Cynthia. Lastly, Dr. Wallace mentioned that he had frequently observed a sound 

 to proceed from the eggs of B. Cynthia, " a sort of click, a single sound, generally 

 in the second week," which was attributed to " the parchment-like shell being pressed 

 out with a spring by the effort of the larva within, and returning to its concave 

 form." 



Mr. F. Moore exhibited Bombyx Guerinii, of which only three or four specimens 

 were known, and Bombyx Ricini, with its cocoons and silk, for comparison with the 

 produce of Dr. Wallace's Ailanthery. 



Mr. Alfred R.Wallace remarked that Dr. Wallace's theory on the relation between 

 the size of the specimen and the period of development satisfactorily accounted for the 

 fact that as a rule in Lepidoptera the male was smaller than the female. Owing to 

 the precarious tenure of life of a Lepidopterous insect, which was not only exposed to 

 the attacks of many enemies, but was also liable to destruction from mere change of 

 temperature, it was important that the female should be impregnated almost as soon 

 as hatched, and therefore that males should be in readiness at the time of her 

 emergence. The males which first hatched became the parents of the future progeny ; 

 the progeny inherited the qualities of the parent; and thus in process of time the 

 males which had a tendency to early hatching, the small specimens which required a 

 shorter period for their development, predominated, while those which hatched later, 

 the larger males, being without mates and therefore leaving no offspring, would con- 

 stantly tend towards extinction, and finally leave the smaller males in possession of 

 the field. 



Mr. Janson exhibited a collection of Coleoptera from Vancouver's Island, amongst 



