I 
MINOT : SINUSOIDAL CIRCULATION. 195 
sue them. Meanwhile we may say that the intertubular circula¬ 
tion has begun to show itself in embryos of 28.0 mm., and that it 
has become sinusoidal in character in close connection with the 
cardinal vein in embryos of 37.0 mm. It seems to me not venture¬ 
some to predict that in older embryos of Squalus acanthias the- 
mesonephros will show a typical sinusoidal circulation. 
Concerning the amphibian and mammalian mesonephros, I have 
nothing to add to what I have said in the earlier paper, ‘98.1. 
The figure of the frog’s kidney is here reproduced, the magnifica¬ 
tion being changed to 300 diameters to facilitate comparison with 
other figures in this article. Of the conditions in the chick a few 
words may be said, to accompany Fig. 5. In the chick, blood sinu- 
demonstrated than in any other 
Fig. 5. Chicken embryo, supposed about 11 days, section of the meso¬ 
nephros. Harvard Embryological Collection, No. 255, section 769. Si, Si, blood 
sinusoids ; t, t, wolffian or mesonephric tubules. 
animal I have studied, and this statement applies equally to the 
Wolffian body, the liver and the heart, see Figs. 5, 6, 7. The 
soids can be more beautifully 
