REDOGENESIS. The larva or maggot of a cer tain gall-gnat fly is known to produce young which is developed within the body of the larva from a 'germ-ball' essentially agreeing with an ovary in appearance. The asexual begin life as egg-like bodies developed from the germ ball, just as eggs are developed in the little tubes of which the ovary is an aggregation. Both Wag ner and Leuckart conclude that the processes of embryonic growth agree in all essential points with the ordinary phenomena of development in a fecundated egg, and exactly as in the ease of Aphis parthenogenesis. The only difference con sists in the germ chambers of the eeeidomyid larvte separating from the germ-stoek. and mov ing freely about in the cavity of the body, while in the aphids, in which then- is no metamor phosis, the gent-stock is a true ovarv. It thus appears that the free mars eel the parent maggot becomes prematurely developed, and the growth of young is thus greatly aeeele rated. The maggots live under the hark I the apple tree in (Icrnmany, Denmark, and Russia, the occurring in t1?0 of tuynda• (ll lash)r inu lroloax and 0/itpire, 8 para..
do.ruS ). Here also belongs the ease of larval r production in Amllysfome.
(..naysm,Loof:NEsms. 'Ibis term is applied by Packard to a form of pa-dogenesis which occurs in the chrysalis of a gnat of the genus hirono inns. In ISfi9 C in rint discovered the pupa of a species of this gnat laying eggs. In :intuu n other pupae changed to Hies without laying eggs, while the tly l‘as observed to deposit a larger number ut eggs than the spring pupa. It is thus seen to be a seasonal phenomenon. de pendent on the temperature. (1rionn also found that on removing from the perfectly developed in sect, before it has left the pupa case, the Which otherwise would have been fertilized, and nurturing them in water, the development of the larvte took place in them also, hut lasted a little longer (about six days).