326 



ME. J. S. BUDGETT ON SOME POINTS IN 



The latter appears actually to be the case in Polyodon folium, where, according to 

 Hyrtl, the duct of the testis, as well as the duct of the ovary, opens into the body- 

 cavity by means of a peritoneal funnel. 



At what stage the opening of the oviduct into the ccelom is acquired in Polypterus I 

 cannot definitely say. It was, however, open in my youngest specimen 9 cm. in length 

 (PI. LII. fig. 22, p.ap.od.). 



In young females 9 cm. in length the genital ducts have not a free opening into the 

 ureter, but, as in the male, the ducts end blindly in the wall of the latter (PL LII. 

 fig. 24, w.o.u.). The communication is complete, however, by the time the young 

 Polypterus is 12 cm. in length. 



Though it would be unwise to form any definite opinion as to the significance of 

 these ducts until their primary origin shall have been made clear, yet, seeing that 



Figs. 1-3. 



OOOQ/- <"""' 



Ovary of Polypterus. 



Fig. 1. — Diagrammatic representation of the developing ovary. 



Fig. 2. — The outer wall of the ovary between each septum beginning to bulge. 



Fig. 3. — The outer wall thrown into deep folds, as in the ripe ovary. 



e.o.w., external wall of ovary ; i.o.iv., internal median wall of ovary ; o', white side of ovum ; 



o"., black side of ovum ; o.s., septum dividing ovary into compartments. 



very immature specimens have been examined, it seems worth while suggesting that 

 the very high development of the genital ducts at an early stage in both sexes, and 

 their similar arrangements, point to their being homologous with one another and also 

 with the embryonic Mullerian duct. The discussion of the a priori objections and the 

 consequences of this conclusion need not here be discussed, in view of the probability 

 of the question being settled by a study of the early development of Polypterus. 



