320 
WILLIAM F. ALLEX. 
most of the space between the lateral body muscles and the 
skin, and extending from one end of the body to the other. 
Cephalad its ending has not been determined, but in the tail 
it terminates blindly, immediately behind the caudal plate. 
Dorsad and ventrad both sinuses hav^e many communications 
with the dorsal and the ventral veno-hnnphatic trunks, and 
through the latter its contents reaches the caudal hearts and 
the caudal vein. Ordinarily, in section (Fig. 1), one of the 
lateral sinuses is much wider than the other, which is likely 
due to the fact that it contains more blood or lymph. 
Relatively there are not nearly as many corpuscles in the 
lateral sinuses of the 20 cm. series as in the 85 mm. and still 
younger embryos. In tlie 85 mm. series one finds the con- 
nective tissue in places outside the lateral sinuses completely 
filled with red corpuscles, having the appearance of germina- 
tive areas. 
From all the median fins numerous sinus-like branches are 
received by both lateral sinuses. The so-called dorsal fin- 
ray canals (Fig. 1, D. S.) come from the dorsal fins, the 
ventral fin-ray canals (Fig. 1, V. S.) from the ventral or 
anal fins, and the caudal fin-ray canals from the caudal 
fins. All of these vessels very closely resemble one another in 
that they more or less envelop a fin-ray, traverse it from its 
distal to its proximal end, and terminate in either the light or 
the left lateral sinus. Each gives off many branches to 
anastomose with the adjacent fin-ray canals (Fig. 1), thus 
forming a very coarse network of vessels in the fin, which, so 
far as could be determined, had no connection with the arteries. 
So far as was observed nearly all of the corpuscles found in 
the veno-lymphatics and in the connective tissues outside were 
red corpuscles, it being necessary to look some time to find a 
leucocyte. In fishes, where death usually occurs after a violent 
struggle, I have attributed the finding of red corpuscles in 
the lymphatics to the rupturing of the delicate walls 
separating them from the blood-vessels. Prof. Carlson 
informs me that an examination of the lymph of mammals 
that have died from violent deaths also resulted in the finding 
