300 
MONICA TAYLOR. 
(3) I have failed absolutely in my former work on Culex, 
although I devoted much time and study to this point, to find 
any figures resembling Metz’s figs. 166 and 167, or Stevens’s 
figs. 8, 9, and 10. This failure may be attributed to differences 
in the material studied. It could not be due to bad fixation. 
(4) Setting aside the Diptera, my figs. 68 and 69 ( 4 ), 
would be interpreted, by the vast majority of cytologists, 
as a split spireme, as chromosomes precociously split for 
metaphase. 
(5) My conclusions in the present paper, made after a 
study of fertilisation, do not differ in principle from those of 
Miss Stevens. I state, for my variety of Culex pipiens, 
that parasvndesis has resulted in actual fusion. Only the 
assumption that some such fusion has taken place can account 
for the striking recurrence of three chromosomes in the 
prophase of somatic tissues in larval, pupal, and imaginal 
material. 
(6) In a preliminary investigation of Chironomus sp., 
an account of which I hope to publish later, I have found a 
confirmation of the results obtained in Culex. 
Literature List. 
1. Dobell and Pringle Jameson (1915). — “ The Chromosome Cycle in 
Coccidia and G-regarines,” ‘Proc. Roy. Soc.,’ vol. lxxxix. 
2. Metz, C. W. (1914). — “ Chromosome Studies in the Diptera. I. A 
preliminary survey of five different types of chromosome groups 
in the genus Drosophila,” ‘ Journ. Exp. Zool.,’ xvii. 
3. Stevens, N. M. (1910). — “The Chromosomes in the Germ Cells of 
Culex,” ‘Journ. Exp. Zool.,’ viii. 
4. Taylor, Monica (1914). — “The Chromosome Complex of Culex 
pipiens,” ‘Quart. Journ. Micr. Sci.’ (n.s.), vol. 60. 
5. Woodcock, H. M. (1914).— “ On ‘Crithidia’ fasciculata in 
Hibernating Mosquitoes (Culex pipiens) and the Question of 
the Relation of this Parasite with a Trypanosome,” ‘ Zool. Anz.J 
Bd. xviii, 8. 
