76 



T. H. Buhlend, 



a portion lateral to the nephrostome) has become included in the 

 nephrotome. 



Textfig. I shows the raesonephric condition intersegmentally 

 where the duct is free from the underlying mesoderm. 



Textfigs. J and K represent the later condition of pronephros 

 and mesonephros with the blood-supply also indicated. 



proi 



nep 

 Textfig. H. 



sp. cd prot 



d.ao neph 

 Textfig. J. 



pr.d ms.t neph nep gl nep 

 Textfig. K. 



Textfig. H. This figure shows how nephrotome encroaches upon the general 

 coelom, and so produces the mesonephric condition. 



Textfig. I. The diagram illustrates the impossibility of the formation of 

 mesonephric tubules intersegmentally. 



Textfig. J. The later pronephric condition. 



Textfig. K. The mesonephric condition is shown on the left in this figure, 

 the transitional stage on the right. 



