710 RECORD OF CURRENT RESEARCHES RELATING TO 



but in other respects tlie form is not that of the male Coccidas, but of 

 the Phylloxeriaus. The head, thorax, and abdomen are united and 

 not separated, as in the former. They are • 4 mm. long, completely 

 apterous, without a rostrum, and with a projecting penis. 



A few days after the appearance of the males the pupae remaining 

 in the cottony mass developed and furnished the female, "45 mm. 

 long, very similar to the form that appears in August, except that it 

 has eight joints in the antennae instead of six, and is therefore a 

 diifcrent phase. Copulation takes place at the time. 



M. Lichtenstein has not yet been able to follow what takes place 

 between May and August, and calls attention to the fact that while 

 these insects exist " in millions " on every elm, the problem of the 

 complete cycle of their life-history, which was set by Eeaumur, is 

 Btill unsolved. 



The specific name of pupifera is given to call to mind the mode 

 of reproduction (Anthogcnesis) in which there intervenes a form fur- 

 nishing male and female pupte from which the sexual individuals 

 issue and immediately copulate. 



Notes on the Phryganida.* — Fritz Miiller draws attention to the 

 fact that the pupte of the Helicopsyclie, which are found in the brooks 

 around him (Blumenau, Brazil) have the first four appendages long 

 and more or less richly ciliated ; in those, however, which are found 

 by the waterfalls, and live on damp stones, the hairs are absent. These 

 examples appear to be of importance as they show in a very striking 

 way the fact that the reduction of parts which have become useless 

 must not be looked upon as being in all cases the simple and direct 

 result of disuse. These swimming hairs are connected with the 

 membrane of the pupa, which covers in the mature insect, so that 

 their being or not being used seems to be a point which would have 

 but slio'ht, if any, efi"ect on the descendants of the insect ; why, then, 

 do they disappear so suddenly when the animal changes its locality 

 to one in which it does not swim, and yet why are such useless parts 

 as the incisors in the upper jaw of the ruminant, which are never cut, 

 continued on generation after generation ? The answer seems to lie 

 in the diflcrence of time that these separate structures have been in 

 the possession of the animal ; where they have been lately acquired, 

 they are, on disuse, easily lost ; but where, as in the case of the 

 ruminant's upper incisors, transmission has been acting for long ages, 

 disuse does not so easily or so rapidly effect complete loss of the now 

 useless structures. 



Anatomy and Physiology of the Digestive Organs of the 

 Myriapoda.t — M. Felix Plateau, in continuation of his researches 

 into the digestive apparatus of the Insecta, now presents a memoir on 

 the Myriapoda, concerning which group the remark of Newport, made 

 more than thirty years ago, " The Myriapoda have been more 

 nerflected by naturalists than almost any other division of the Articu- 

 lata," still remains true. 



* 'Zool. Anzciger,' ii. (1879) p. ISO. 



t ' Mem. Acad. Roy. Sci. Belg.," xlii. (1878), Art. ii. 



