SPERMATOGENESIS OF THE MYRIOPOn-. 139 



majority of the -lides having been mounted nine years, but the 

 -tain Heidenhain'- iron-alum haematoxylin), except where a por- 

 tion of i In- -ection extends from under the cover-glass, is as perfect 

 a- \\ hen tir-t mounted. 



Sutton, 1 :O2, Robertson, 2 :o8, and Xowlin, 3 :o8, working upon 

 ih- male cell- of ( )rthoptera have found that the chromosomes 

 during both the -permatogonial and spermatocyte generations 

 may be arranged in a graded series as regards size. In the sper- 

 tin- -eries is a double one, the two chromosomes of a 

 -i/r repre-enting the similar elements derived from the 

 t\\'> parent-. The-e -imilar chromosomes unite during synap-i- 

 Snt ton. :<t2.t>f>. fit.), and give rise to the single series character - 

 i-tic "f tin -pcrm.itocytes. The extreme difference in the si/e 

 of the chionio-,,nn-s in the Orthoptera is so marked that it i- 

 IK -I iceable at a glance (see Sutton, :02, Fig. 6) and after stiuh inu 

 preparation- of thi, material one cannot doubt the accuracy "f 

 their observation- ,,r deny the strength of their conclusions, that 

 in the-e lorin- the chromosomes at any given stage bear a certain 

 -i/e i el at ion to t-ach other, and that this presents strong evidence 

 in -uppoit IP! tlu- theory of the individuality of the chromosomes. 



lint it ue i^rani the>e conclusions with regard to the form- 

 -tndied. dm - it necessarily follow that these conclusions should 

 be made nioiv general and applied to the chromosomes of all 

 animal-.' What shall we say as regards the application of this 

 te-t to tin- chromosomes of a form in which the difference in 

 -i/e i- not - ..... arked or in \\hich the chromosomes all appear of 

 nearU one size? Such is apparently the case in Scolopendra. At 

 ordinary magnification there is very little difference in the si/e 

 it the chroiim-c .me- as seen in a metaphase of the first spermato- 

 ( \ t. dillereiice is to be detected even at a magnification 



a- lnu as i.ooo diameters, but this is so slight that if size alone 

 be u-ed a- a criterion it would seem impossible to distinguish be- 

 t \\een the chroino-omes farther than to say: "This is one of the 

 -mallei one-" or "one of the larger ones." 



. \V S.. :o2. "On the Morphology of the Chromosome group in Bra- 



'i'i," Him- BVLL., \"ol. 4, pp. 24-39, " "8- 

 K. i .. rtson, \\ . K. B., :o8, "The Chromosome Complex of Syrbulii ailmira^ilis." 



S null.. \'ol. 1\".. pp. 275-305, 5 plates. 



'Nmvlin. Na.line, :o8. "The Chromosome Complex nf Melanoplus biiittatus 

 - i. Intll.. \'<>1. I\"., pp. 265-271. 2 plates. 



