204 



wards, the MüUerian duet dilates, the external wall of the 

 WolfiGan duet adjoining it becoraes greatly thiekened and pushed 

 iu in its middle part, so as almost to toueh the opposite wall 

 of the duet , and so form a bay in which the Müllerian duet 

 lies. As soon at the Müllerian duet has eome to lie in this 

 bay its walls lose their previous distinetness of outline, and 

 the cells eomposing them assume a curieus vacuolated appea- 

 ranee. No well-defined line of separation ean any longer be 

 traeed between the walls of the Wolffian duet and those of 

 ihe Müllerian , but between the two is a narrow elear spaee 

 traversed by an irregular network of fibres, in some of the 

 meshes of which nuclei are present. 



The Müllerian duet may be traced iu this coudition for a 

 considerable number of sections, the peeuliar features above 

 described becoming more and more marked as its termination 

 is approached. It continues to dilate and attains a maximum 

 size in the section or so before it disappears. A lumeu may be 

 observed in it up to its very end , but is usually irregular in 

 outline and frequently traversed by strands of protoplasm. The 

 Müllerian duet finally terminates quite suddenly , and in the 

 section immediately behind its termination the WolflSan duet 

 assumes its normal appearance, and the part of its outer wall 

 on the level of the Müllerian duet comes in contact with the 

 germinal epithelium". 



Maar zelfs afgezien van h^t feit , dat de bijzonderheden in 

 bovenstaande beschrijving niet volkomen op mijn embryo's van 

 toepassing zijn , en dat deze te dien opzichte ook onderling vrij 

 wat verschillen , moet ik dadelijk de opmerking maken , dat ook 

 deze wijze van samenhang bij de door mij onderzochte vogels 

 misschien nooit geheel zuiver voorkomt. Bijna altijd is ui. het 

 uiterste einde van de Müllersche gang duidelijk in veel inniger 

 samenhang met den wand van de Wolffsche. •>->Diclit bij het 

 uiteinde nog zeer duidelijk loaar te nemen , wordt de verbin- 

 ding verder kopwaarfs meer en meer twijfelachtig, is dikwijls 

 over eenige sneden geheel afgebroken om zich telkens, zij het 



