611 



may be the specialization involved, in accord with the theory of 

 ZiEGLBR and VON Eath. The histologic data from the ciliated cells of 

 the epididymis of the mouse and other forms supports indirectly the 

 hypothesis of Child, namely, that amitosis signifies lack of adequate 

 nutritional supply. It moreover extends the probable explanation 

 of amitosis a step farther in that it indicates that the point of incidence 

 of specific effect of nutritive inadequacy, or otherwise unfavorable 

 condition, is the centrosome of the cell.^) 



Literature Cited. 



Child, C. M. 1907 a. Amitosis as a Factor in normal and regulatory Growth. 

 Anat. Anz. 30, No. 11 and 12. 



— 1907 b. Studies on the Relation between Amitosis and Mitosis. Biol. Bull. 

 12; 2, 3, and 4. 



Dahlgren, U. and Kepner, W. A. Principles of Animal Histology, The 

 Macmillan Co., N. Y. 1908. 



Fuchs, H. 1902. Über das Epithel im Nebenhoden der Maus. Anat. Hefte. 



Nathänsohn, A. 1900. Physiologische Untersuchungen über amitotische Kern- 

 teilung. Jahr. f. wiss. Bot. 35 ; 1. 



Patterson, J. T. 1908. Amitosis in the Pigeon's Egg. Anat. Anz. 32, No. 5. 



Prenant, A., Bouin, P. et Maillard, L. Traite d'Histologie. Tome 1. Cyto- 

 logie generale et speciale. Maison et Cie., Editeurs, Paris. 



Richards, A. 1911. The Method of Cell Division in the Development of the 

 Female Sex Organs of Moniezia. Biol. Bull. 20; 3. 



4) To test experimentally the hypothesis that amitosis is correlated with 

 loss of integrity, or inability for normal function, on the part of the centro- 

 some, onion roots were grown in water to which ether was added; on the 

 assumption that the analogue of a centrosome is here active, though indis- 

 cernible, in the formation of the achromatic spindle. In a similar experiment 

 with roots of Phaseolus, Lupinus, Phalaria, and Marsilia, Nathansohn (loc. cit.) 

 was unable to produce any effect in the direction of amitosis. Wasielewski 

 (Jahrb. wiss. Bot., 1902, 38 : 2 ; also 1904, 39 : 4), however, succeeded in in- 

 creasing the relative number of amitoses in roots of Vicia faba, treated with 

 chloral hydrate solution ; but Nemec (ibid., 1904, 39 : 4) disputes the accuracy 

 of the interpretation, and explains the appearances in terms of nuclear fusions. 

 At present and desire only to state that onion roots grown in water with 

 ether show numerous amitotic divisions, and very few mitoses, thus confir- 

 ming the general validity of the hypothesis that amitosis follows centrosomic 

 incapacity. The experiments as continued and checked by controls will be 

 fully described in another place. 



