1865.] Zoology and Animal Physiology. 135 



have as yet only yielded so few species (of Strepsiptera none has been 

 found) that they are not here noticed. Of the above, the Hymenoptera 

 are principally made up of the families Ichneuinonidas and Aphidae — 

 the Lepidoptera of the small moths — the Diptera, by the Muscidae — 

 the Homoptera, by the Cecropidae, and the Orthoptera, by the Locus- 

 tidaa. With the exception of the last, this seems much the same as in 

 European countries. 



M. Baudelot, struck with some experiments by M. Faivre, which 

 had led the latter to suppose that the respiratory movements of insects 

 have their origin in a special region of the nervous system, as in 

 Mammalia, has conducted a series of experiments to test the matter, 

 the result of which has been to prove that the metathoracic ganglion is 

 not the prime mover of the respiratory motions, as was believed by 

 Faivre. The experiments were made upon Dyticus, and the lava of 

 Libellula, and he has proved that each abdominal ganglion supplies 

 nerve-force, and co-operates as far as it can to the accomplishment of 

 the respiratory action of the whole. And it is remarkable that, after 

 the sections of the nervous cord, the isolated action of a ganglion 

 appears to be by so much weaker wben it is united to a smaller num- 

 ber of other ganglionic elements. When oue takes into consideration 

 the division in the rings of the body and of the abdomen of the Arti- 

 culata, a division frequently so much in harmony with the nervous 

 element — when one sees in Crustacea the breathing apparatus occupy 

 so many varied positions, now at the level of the thorax, now of the 

 abdomen, and see them receive nerves from so many different points — - 

 it was hardly possible to admit that insects have a special nervous centre 

 for the functions of respiration. 



Dimorphism, which has been found to occur so frequently both in 

 animals and vegetables, has been observed in the gall insects (Cynips) 

 by Mr. Walsh, who has recorded his observations before the Entomo- 

 logical Society of Philadelphia. Part of the gall produced males and 

 females of C. spongifica (in June), while another part, of wholly simi- 

 lar general character, remain green till autumn, and in October and 

 November produced another form of Cynips (C. aciculata), hitherto 

 regarded as a distinct species, all the individuals of which are females, 

 and although widely different in many characters, appears only to be 

 a dimorphic condition of the first. These (C. spongifica) live ouly six 

 or eight days, and Mr. Walsh suggests that the female C. aciculata 

 generates galls which produce, by parthonogenesis, male C. spongifica, 

 and that the females and males of the latter, coupling in June, oviposit 

 in the same month in the young buds of the oak, eggs that remain 

 dormant till the following spring, some of which then produce female 

 C. spongifica in June, and some female C. aciculata in the autumn, or 

 early in the following spring, and these last in their turn, generate male 

 C. spongifica to appear in the following June. And he justifies his 

 opinion by mentioning some of the analogies which have been observed 

 in other hymenopterous insects. 



M. de Quatrefages has communicated to the Academic des Sciences 

 some remarks upon the geographical distribution of the Annelida, and 



