NEW TYPES OF CHROMOSOME DISTRIBUTION. 163 



or four, the female has the larger quantity of chromatin with 

 the possible exception of Acholla multispinosa. Here the male 

 seems to have the greater quantity and this inequality is brought 

 about by the differential chromosomes themselves. This argues 

 further against the interpretation that sex is determined by a 



quantitative relation of the chromatin. 

 ZOOLOGICAL LABORATORY, 

 COLUMBIA UNIVERSITY, 

 December 16, 1908. 



LITERATURE. 

 Arnold, G. 



'08 The Nucleolus and Microchromosomes in the Spermatogenesis of Hydro- 



philus piceus (Linn.). Archiv fiir Zellforschung, Band II., Heft i. 

 Baehr, W. B. von. 



'08 Uber die Bildung der Sexualzellen bei Aphididse. Zoologischen An- 



zeiger, Bd. 33, Oct., 1908. 

 Baumgartner, W. J. 



'04 Some New Evidence for the Individuality of the Chromosomes. Biol. 



Bull.. 8, i. 

 Baltzer, F. 



'08 Uber die Grosze und Form der Chromosomen bei Seeigeleiern. Ver- 

 handlungen der Deutschen Zoologischen Gesellschaft. Vierte Sitzung. 

 Blackman, M. W. 



'03 The Spermatogenesis of the Myriapoda. 2. On the Chromatin in the 



Spermatocytes of Scolopendra heros. Biol. Bull., Vol. 5. 

 '05 The Spermatogenesis of Scolopendra heros. Bull. Mus. Comp. Zool., 



Harvard, 48. 

 Berry, E. H. 



'06 The ''Accessory Chromosome" in Epeira. Biol. Bull., XL, p. 193. 

 Boring, A. M. 



'07 A Study of the Spermatogenesis of 22 Species of the Membracidae, 



Cercopidse and Fulgoridze. Journ. Exp. Zool., IV., 4. 

 Castle, W. E. 



'03 The Heredity of Sex. Bull. Mus. Comp. Zool., Harvard, Vol. 40, No. 4. 

 Foot, K., and Strobell, E. C. 



'07 The " Accessory Chromosome " of Anasa tristis. Biol. Bull., XII., 



p. 119. 

 'O7a A Study of the Chromosomes in the Spermatogenesis of Anasa tristis. 



Amer. Journ. Anat., 7. 

 Gross, J. 



'04 Die Spermatogenese von Syromastes marginatus. Zool. Jahrb., Anat. 



und O.itog., XX., 3. 

 '06 Die Spermatogenese von Pyrrhocoris apterus. Zool. Jahrb., XXIIL, 



p. 269. 

 Henking, H. 



'91 Ueber Spermatogense und deren Beziehung zur Eientwicklung bei 

 Pyrrhocoris apterus. Zeitschr. Wiss. Zool., 51. 



