THE KANSAS UNIVERSITY 

 SCIENCE BULLETIN. , 



Vol, V, No. 20.] MARCH, 1910. [^rxVxoTo 



AN EXAMINATION OF THE CHROMOSOMES OF 

 ANASA TRISTIS. 



BY C. E. M'CLUNG AND EDITH PINNEY. 



I. Introductory statement. 



II. The chromosomes during the spermatogenesis of Anasa, an inde- 

 pendent study: By the junior author. 

 III. A comparison of the results of studies upon the chromosomes of 

 Anasa: By the senior author. 



1. Methods. 



2. What is the number of spermatogonia! chromosomes, and of 



oogonial chromosomes? 



3. What is the number of first spermatocyte chromosomes? 



4. What is the behavior of the accessory chromosome and of the 



plasmasome in the first spermatocyte prophase? 



5. What is the behavior of the accessory chromosome in the first 



spermatocyte mitosis? 



6. What is the behavior of the chromosomes in interkinesis? 



7. What is the behavior of the accessory chromosome in the second 



spermatocyte mitosis? 



8. What is the final chromosome constitution of the spermatozoa? 



I. INTRODUCTORY STATEMENT. 

 The extensive studies now in progress upon the chromo- 

 somes of numerous species of plants and animals have led to 

 the formulation of several working hypotheses of considerable 

 general importance. In order that these may be of value and 

 serve as an aid to further progress, it is necessary that the 

 phenomena from which they take their origin be extensively 

 recognized and uniformly interpreted. Any conception of the 

 relations existing between germ-cell organization, as exhib- 

 ited by the chromosomes, and the structural characters of the 

 body is now unfortunately delayed by certain disagreements 



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