NOTES 123 



Foote and Stiobell, 1907, Biological Bulletin, XII. 

 Foote and Strobell, 1907, American Journ. Anai., VII, 279-316. 

 Lefevre and McGill, 1908, American Journ. Anat., VII, 469-485. 

 C. V. Morril, 1909, Biological Bulletin, XIX. 



C. E. McClung and Edith Pinney, An examination of the chromo- 

 somes of Anasa tristis. The Kansas University Science Bulletin, V, No. 

 20, 349-380. 

 To those who would like to acquaint themselves further with this sub- 

 ject, this excellent article is especially recommended. It is distinguished 

 by its concise, clear and exhaustive presentation. 



46. Miss N. M. Stevens studied chromosomes in many insects with great 

 skill and success. 



1908. Diptera. Journal Exp. Zoology, V, 359. 



1908. Diabrotica. Journ. Exp. Zoology, V, 453. 



1909. Coleoptera. Journ. Exp. Zoology, VI, loi. 

 1909. Aphidse. Journ. Exp. Zoology, VI, 115. 



Compare also Biol. Bull., XVIII, 73-75, 1910. 



47. Miss N. M. Stevens. Preliminary note on heterochromosomes in the 

 guinea-pig. Biol. Bulletin, XX, 1 21-12 2, 191 2. 



Heterochromosomes in the guinea-pig. Biol. Bulletin, XXI, 155-167. 



48. Michael F. Guyer, The spermatogenesis of the domestic guinea (Numidia 

 meleagris dom.). Anat. Anz., XXXIV, 502-513, 1909. 



Accessory chromosomes in man. Biol. Bulletin, XIX, 219-234. 



49. T. H. Morgan, A biological and cytological study of sex determination 

 in Phylloxerans and Aphids. Journ. Exp. Zoology, VII, 239-352, 1909. 

 (Also several preliminary communications.) 



50. H. S. Pratt, Science, 191 2. The author states the following estimations 

 of the number ,of known species of animals: 



Linne 1758 4,236 



Agassiz and Bronn 1859 129,530 



Ludwig (Leunis) 1886 272,220 



Pratt 1911 522,400 



51. Helmholz is not the author of the hypothesis that meteorites brought 

 life to our earth. As early as 1871 it was introduced by Sir WiUiam 

 Thompson in his Presidential Address before the British Association. So 

 also the hypothesis of Arrhenius, which, according to Schafer, was orig- 

 inated by Cohn (1872) and Richter (1875). 



52. E. Pfliiger, Ueber die physiologische Verbrennung in den lebendigen 

 Organismen. PflUgers Arch, gesamt. Physiol., X, 251-367, 1875. (See 



P- 339 ff-) 



53. T. H. Morgan utilized DrosophUa for many experiments on heredity. 



