164 



After describing bis metbod of work and the manner in wbicb the 

 eggs and other material were prepared for study, the author discusses 

 the formation of the eggs in the ovaries ; oviposition and the subse- 

 quent development of the embryo, including a discussion of the forma- 

 tion of germ layers and embryonic envelopes, together with a descrip- 

 tion of the external change in the embryo of Blatta and the subsequent 

 stages in the evolution of the embryo in Doryphora. 



The author concludes with a list of the authorities referred to in the 

 course of his work. The article covers 92 pages and is illustrated with 

 16 text figures and 7 large lithographic plates. 



Willow and Poplar Insects.— In Bulletjn No. 9 of the Agricultural Ex- 

 periment Station of the University of Minnesota, the first portion of 

 which contains a consideration of Russian willows and poplars, we find 

 some sixteen pages by Prof. O. Lugger, treating of insects affecting 

 poplars and willows. He describes at some little length, with figures, 

 Cimhex americana, Nematus ventralis, Una scripta, L. tremulae, L. lap- 

 2Jonica, Saperda calcarata, S. concolor, Vanessa antiopa, Hyphantria cunea, 

 Acronycta lepusculina, Platysamia cecropia, and Telea polyphemus. The 

 articles are brief and popular, and contain for the most part restatements 

 of well known facts; but the author mentions that Cimhex americana is 

 attacked by a Tachinid fly in Minnesota. The work of the Poplar 

 Girdler {Saperda concolor) is for the first time illustrated, and a number of 

 different species of parasitic Ichueumonidie are reported to have been 

 bred from it. Acronycta populi, Riley, is made a synonym of A. lepus- 

 culina, Guenee, following Grote; but this is an error, the latter species, 

 known to us, being different in both larva and imago, and occurring on 

 the Pacific coast. 



Another Importation from Europe.— Prof. J. H. Comstock, in Bulletin No. 

 11 of the Agricultural Experiment Station of Cornell University, has 

 given in detail an account of the life-history of the well-known Euro- 

 pean Corn Saw -fly [Cephus pygmaeus), which, curiously enough, he finds 

 very abundantly in wheat on the university farm. This insect has not 

 previously been recorded in this country. Professor Comstock finds 

 that the adults emerge early in May, oviposit about the middle of the 

 month, and that in a very short time the larvse work through nearly 

 the entire length of the straw, descending early in July to the root. 

 Here, after cutting the straw nearly through an inch above the ground, 

 they spin silken cocoons and remain dormant until early the following 

 spring, when they complete their transformations. 



He finds that their presence in the stalk reduces the abundance of the 

 grain little, if any, and that the principal damage is the lodging of the 

 grain. He has found the species in wheat alone. He has seen para- 



