1865.] Entomology. 669 



metal in the leaves and trunks of trees growing on the soil. It is 

 pointed out that the amount of manganese in the lias is considerably 

 above that in the oolite. 



Professor Church also publishes some analyses of bronzes found 

 in Great Britain, which show that much of the so-called bronze of the 

 Roman period should be called brass, being composed principally 

 of copper and zinc. A specimen of Celtic bronze, analyzed by 

 Mr. Church, was mainly composed of copper, tin, and lead, while 

 another was principally copper and zinc. 



V. ENTOMOLOGY. 



{Including tlie Proceedings of the Entomological Society.) 



In June, 1861, Professor N. Wagner, of Kasan, accidently found what 

 he calls "the spontaneously multiplying larvae of," to him, an "un- 

 known member of the Diptera."* These larvae were filled with other 

 larvae exactly like them. At first he thought it was a case of parasitism, 

 but after examining many of them, he became convinced that the 

 secondary larvae had been developed from " embryonal bodies " indis- 

 putably belonging to the organism of the parent larvae. This discovery 

 does not appear to have excited much attention ; an American author, 

 however, considers the statement to be " a pure and simple delusion." 

 In a recent number of Siebold and Kolliker's Zeitschrift fur Zoologie 

 (1865, p. 106) Professor Wagner enters into a long and elaborate 

 account of his observations. He says that " in carefully watching the 

 larvae every day one sees clearly that new larvae crawl out of them, 

 and, like them, in from seven to ten days bring forth other new larvae." 

 Some of these he kept by him during the winter, and the larvae 

 multiplied in this way all the time. The pupa state was assumed 

 from the 6th to the 8th of June, and three or four clays after the 

 insects came forth. The " embryonal bodies " differ from eggs, in that 

 they arise from alterations in the organism, while eggs are developed 

 in special sexual organs. In the first case, impregnation is never 

 necessary, and to this category of organic generations Professor 

 Wagner would confine the term " Parthenogenesis." More recently 

 Professor von Siebold, having had some of the larvae sent to him, is 

 satisfied that the young larvae are really produced by the mother larvae, 

 and therefore " that all thoughts of their being parasites must be 

 given up." 



The conclusions of Mr. Walsh respecting dimorphism in the 

 Gall-flies f appear to have met with less acceptance in Germany 

 than in this country. M. Eeinhard, of Bautzen,! considers that 



* It is the Miastor metraloas of Meinert, and belongs to the sub-family 

 Cecidomyinse. A well-known species in this group is the wheat-fly (Cecidomyia 

 tritici). 



t 'Proc. Entom. Soc. of Philadelphia,' March, 1864. 



t ' Be liner Entom. Zeitschrift,' 1855, p. 1 et seq. 



2z2 



