INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 939 



the female, is probably to enable the male to exercise a charm over its 

 partner. 



The importance of these modified scales is greater than that of 

 the normal ones which colour the wings, as these are almost invisible 

 in the dnsk ; and they show an important connection existing between, 

 scent and alimentation, for it is found that insects choose, as flowers 

 from which to feed, those whose scent most nearly resembles their 

 own. The privet hawk-moth, for instance, prefers the musk-scented 

 Weigelia, and second to it, the Petunia, smelling of honey and musk ; 

 the Zyrjoence, which emit an odour like that of honey, prefer the honey- 

 scented Scabious best. 



Morphology of the Suspensory Organs of Chrysalids.* — 

 M. Kiinckel points out how little knowledge as to this subject has 

 been definitely acquired sinco the time of Reaumur. That eminent 

 naturalist described how the tail of the chrysalis was separated from 

 the integument of the caterpilhir, and bec:ime attached by the hooks 

 with which it is furnished. The author has again investigated this 

 subject, and has come to the conclusion that the chrysalids have no 

 real tail at all. 



Examining the chrysalis of Papilionids or Nymphalids, he has 

 seen that the " tail " is formed by the union, along the median line, 

 of a pair of appendages ; these have each a series of hooks, and they 

 belong to the twelfth ring of the chrysalis, in which there are no 

 stigmata. The appendages surround the extremity of the abdomen 

 and circumscribe the anus ; when ccdysis occurs the Pajjilio, on 

 losing its suspensory apparatus, loses its anal appendages. These 

 last may, especially in many genera of the Notodontidfe, take on very 

 various forms. In Dicranura they are two retractile prolongations ; 

 in Platypterijx they are united for some part of their length, and arc 

 no longer retractile ; in Uropus they are somewhat similar to the 

 same parts in Dicranura, but they have a more distinct pediform 

 character, and they also have a crown of hooks. Their power of 

 modification easily leads us to see how they became suspensory organs. 



Further information may be gained by taking a caterpillar, just 

 before the period of metamorphosis is completely reached ; the best 

 examples are to be found among species of the genus Vanessa. If 

 ccdysis be hastened by treatment with alcohol or chromic acid, it is 

 possible to see that the posterior extremity of the chrysalis is 

 entangled in the twelfth ring of the caterjjillar, and that the parts 

 which carry the suspenscjry liooks (the " tail " of many authors) aro 

 hidden under the integument of the anal appendages of the 

 caterpillar. 



It follows, therefore,. tliat the chrysalids of tlio Lcpidoptcra attach 

 or suspend themselves by tlie hooks of the membranous anal 

 apiieudages, wliich are modified and adapted to the special conditions 

 of tlieir life. 



Preservation of the Chrysalis from Cold.t — Dr. Jousset do 

 Dcll«;snie was led to the consideration of the question whether tho 



♦ 'Omiptes Uendii.-',' \c\. (1880) p. 395. 



t ' La Nature,' viii. (1880) 1" si'incstrp, p. 8H. 



