1578 Journal of Applied Microscopy 



extruded from the egg, while the inner copulates with the second polar body, 

 forming a large nucleus. This nucleus soon disintegrates in the fertilized eggs, 

 but in the parthenogenetic eggs divides repeatedly, taking part in the formation of 

 eight cells, which wander into the central portion of the egg, where their ultimate 

 fate could not with certainty be determined. No copulation occurs between the 

 female pronucleus and either of the polar bodies. How the normal number of 

 chromosomes is regained in the parthenogenetic eggs, repeated efforts failed to 

 discover. s. j. h. 



Montgomery, T. H. A Study of the Chromo- This paper is divided into two portions. 



somes of the Germ Cells of Metazoa. ^he first is devoted to detailed observa- 



Trans. Am. Philos. boc, 1901. 



tions on the spermatogenesis of forty- 

 two species of Hemiptera. The subjects that received especial attention are 

 the changes that occur during the synopsis stage, the reduction in the number of 

 chromosomes, and the chromatin nuclei. The interesting discovery is recorded 

 that in four species of Hemiptera the normal number of chromosomes is odd. 

 In the second portion of the paper there is a discussion of subjects of a general 

 nature, chief of which are the following : The individuality of the chromosomes, 

 the significance of the chromatin nucleoli, the relation of number of chromosomes 

 to genetic affinity, the factors which determine the number of chromosomes, 

 significance of the uneven number of chromosomes, and the problem of reduction. 



S, J. H. 



^""^'i^-^'A ^m'''%'' zur Entwicklungsge- Investigation was carried on mainly 

 schichte der Musciden. Zeit.wiss. Zool.,1901. * ^ 



upon CaJliphora erythrocephala. The 



following subjects are treated : The first developmental changes in the fertilized 

 egg, formation of polar bodies, origin of the yolk cells, forniation of the blasto- 

 derm and germinal layers, development of the alimentary canal, and the fate of 

 the pole cells. In regard to the last subject the author finds that the pole cells 

 wander into the archenteron, becoming embedded finally in the entoderm, where 

 their further fate could not be followed. s. j. h. 



The author uses a mixture of 2 pts. 80 

 Henninp, C. Dr Depigmenting the Eyes of ^ ^i^oj^^i ^^^ ^ ^ glycerin to 



Arthropoda. Zeit. \\ iss. Mick. 17, 1900. ^ _ r ts j 



which 2 vols, of strong sulphuric 

 acid are added. The solution acts best at a temperature of about 35° C, the 

 time required varying from 10 minutes to about 12 hours according to the kind 

 of pigment. The prolonged action of the fluid is not injurious to the eye 

 tissues. A. M. c. 



CURRENT ZOOLOGICAL LITERATURE. 



Charles A. Kofoid. 



Books and separates of papers on zoological subjects should be sent for review to 

 Charles A. Kofoid, University of California, Berkeley, California. 



Harvey, N. A. Introduction to the Study of ^^ elementary laboratory manual, the 

 Zoology for the use of High Schools and ^ ■' 



Academies. 208 pp. 190 1. The Western outgrowth of the normal school method, 



Publishing House, Chicago. p^^ fo^^h as a guide for work in the 



