318 Mtscellaneous. 



the number of joints of the antennae and caudal seta3, the curioua 

 development of the eyes, the appearance of the respiratory organs 

 and their gradual transformation, &c. Not one of the points touched 

 on by M. Joly, but has been already treated with a master hand 

 by Lubbock. Every thing seems to go on in an identical manner in 

 the two larvae, except as regards the caudal setae. Thus M. Joly 

 figures an embryo of Palingenia, artificially released from the egg 

 before hatching, in which Ave see the three caudal sette equal to 

 each other ; in the CMoeon, on the contrary, only the two lateral 

 filaments exist in the very young larva, the median filament being 

 developed only at a later period and gradually. The metamorphosis 

 is therefore more complete in this respect in Chloeon than in Palin- 

 rienla. This difference is not of great importance, and would not 

 have sufficed to lead us to dwell upon M. Joly's memoir; but the 

 conclusions which the author draws from his observations seem to us 

 to be erroneous and to requii-e contradiction. 



M. Joly thinks he has discovered a new case of hypermetamorpJiosis, 

 and tries to find in the development oi Palingenia evidence of a trans- 

 ition between Insects and Crustacea. 



How can the development of the larvae of the Ephemeridae, which 

 takes place so gradually, without sudden and stronglj- marked trans- 

 formations and without the intercalation of pupoid forms, be com- 

 pared with that of Sitaris, in which M. Fabre has ascertained the 

 existence of a primitive larva, a second larva, a 2'>seiido-pupa, and a 

 third larva, forms which mark so many phases clearly separated 

 from each other ? In the Cantharidae there are metamori)hoses 

 during the larval state ; in the Ephemeridae there are only changes 

 of skin accompanied by those gradual changes which constitute pre- 

 cisely the character of the Tnsecta Hemimetabola. If we should 

 apply the name of hypermetamorphosis to the larval development of 

 the Ephemeridae, which is so continuous and so graduated, what 

 name shall we have to coin for the curious transformations of the 

 Pteromalina) described by Ganin?* 



As to the transition between the Insects and Crustacea, which the 

 author desires to establish upon vague analogies between certain 

 systems of organs, it seems to us to be rather rash. We can suppose 

 the existence of a common stock from which the Insecta and the 

 Myriopoda would have originated, or at least a portion of the latter. 

 These two classes are bound together in existing nature by the Or- 

 thoptera (Thysanura) on the one hand and the Chilopoda on the 

 other. The genera which form the bridge between the two groups 

 are Nicoletia, Campodia, Seolop>endreUa (S. immaculata), and perhaps 

 Pauropus. It is even difficult to decide absolutely whether Scolo- 

 pendrella should be referred to one class or the other. But the 

 affinities between the Orthoptera and the Crustacea are certainly 

 much more distant, and we must ascribe the value of homologies to 

 mere superficial analogies. — A. Humbert, Bibl. Univ. December 15, 

 1872, Bull. Sci. p. 415. 



* "Beitrage zur Erkenntniss der Entwickelungsgeschichte bei den In- 

 sekten," Zeitsclir. fiir wiss. Zool. Bd. xix. (1869) pp. 881-451. 



