B. F. Kingsbury 121 



dinal splitting, and the process is reduced to the typical form." Such 

 a transverse division is not believed to occur in Desmognathus, however, 

 and the above is written simply to present all the possibilities of inter- 

 pretation. If we compare other Amphibia we find that the occurrence 

 of a fusion between the apices of the daughter- Vs with X-formation 

 does not exist as far as reported, save perhaps in the oogenesis of the 

 Triton, as investigated by Camoy and Le Brun, 98. Flemming, 87, in 

 his work, indeed, did not recognize that the longitudinal splitting of 

 the chromosomes of the secondary spermatocyte took place early (in 

 the previous cell generation), nor that the splitting of the daughter- 

 chromosomes in the anaphase of his heterotypic mitosis was the preco- 

 cious splitting for a second, following division; though he recognized its 

 importance and normal occurrence, he confessed ignorance as to its 

 significance. Meves, 96, leaves no doubt that this second precocious 

 splitting becomes completed in the spermatocyte of the second order 

 as the longitudinal division of the chromosomes of that cell division; 

 his words are: "Die zweite homootypisch verlaufende Eeifungstheilung 

 schliesst sich an die erste heterotypische an, ohne dass ein eigentliches 

 Euhestadium des Kerns durchlaufen wurde, sondern dieser tritt aus dem 

 Dispiremstadium von neuem in Mitose. Indem sich die chromatischen 

 Faden aufiockem, wird zunachst die im Dyaster der heterotypen Form 

 aufgetretene Langsspaltung welche wahrend des folgenden Dispirem- 

 stadiums undeutlich geworden war, von neuem sichtbar" (p. 61). Mc- 

 Gregor,* too, inclines to the same result in Amphiuma, Avhile Eisen does 

 not refer to the steps in sufficient detail, stating simply that both divi- 

 sions in Batraclioseps are equation divisions. Carnoy and Le Brun, 98, 

 in their work on the oogenesis of the Tritons, agree with the other 

 workers on Amphibia in that they find both divisions are longitudinal. 

 Their results are unique in several particulars. Their figures show the 

 occurrence in the oogenesis of Triton, of X's entirely similar in appear- 

 ance to the structures in Desmognathus, though it does not appear that 

 they are daughter-V's united at their apices and formed by an incom- 

 pleted longitudinal splitting. Their figures illustrating the second longi- 

 tudinal splitting do not appeal to me as satisfactory, and perhaps permit 

 of a different interpretation. The two divisions in the oogenesis of the 

 Tritons follow each other more rapidly, so that a species of tetrad- 



•* " The chromatin emerges from the spirem in the form of twelve Vs longitudinally 

 split, which are probably identical with those of the anaphase of the preceding 

 division, though this cannot be stated with absolute certainty, for it is impossible to 

 discover exactly how the new double Vs arise from the spirem." McGregor, 99, 

 p. 80. 



