346 s. HATTA : 



in other places, for instance, in the space between the lateral 

 plate and the epiblast (figs. 79-81, mch.), I have been compelled 

 to conclude that they have no genetic relation with the pronephros, 

 but are niesenchymatous cells which are destined to form the 

 blood-vessels and corpuscles. 



As the embryo was somewhat twisted, the sections did not 

 pass through the lateral walls of the body in an exactly trans- 

 verse plane, but unavoidably obliquely, on either side, as the 

 continuous serial sections represented in figs. 70-86 show. 



While on the left side of fig. 78 the posterior portion of the 

 second tubule {pt.2) is seen, the second nephrostome {nst.2) is ob- 

 served on the right together with a cross-section of a tubular struct- 

 ure (ed.). This latter might be taken as a slice of the anterior 

 border of the second tubule, but is, in my opinion, the remnant of 

 the collecting duct which once connected the second tubule with tlie 

 first and forms, at present, a tubercle in front of the second tubule, 

 the first tubule having disappeared ; for the second tubule on that 

 side is observable in the next following section represented in 

 fig. 79 {pt.2) showing its characteristic features stated above 

 (p. 342). 



On the left side of fig. 79 and on the right side of fig. 81, 

 we see the anterior half of the third tubule {pi.S) and nephro- 

 stome {nsL3) of each side, their respective posterior half being 

 found on the left side of fio-. 80 and on the risjht side of fis;. 

 82 {pt.3 and 7isL3) ; the tubules are bent laterally and dorsally, 

 probably caused by the prolongation of their tubular portion ; for 

 their nephrostomal part and dorsal blind end retain their original 

 position. This is the first step in the convolution of the pro- 

 nephric tubule. 



As seen on the left side of figs. 79 and 80, the tubule {pt.3) 



