326 



an average red blood corpuscle. The presence of these channels at once 

 explains the appearance of blood in the peribranchial sinuses in the 

 normal living fish, and it seems certain that there must be other 

 connections between the blood vessels and the so-called lymphatic 

 spaces in other parts of the body. 



Variation. 

 In working out the seemingly endless variations in the constrictor 

 muscle of the gills, I recently came upon what seems to be a rarely 

 recorded variation. On the left side there were 7 gills, of which the 

 additional one seemed to be the last, since it was supplied by a twig 

 given off from the last afferent branchial artery. On the right side 

 the normal 6 gills were present. In the same specimen the ventral 

 aorta was continued forwards as an unpaired artery on to the club- 

 shaped muscle. In another specimen, dissected by one of my senior 

 students, Miss M. K Hartley, there were 7 gills on both sides. On 

 the left side all the gills were of much the same size, except that the 

 middle ones were slightly the larger, and there were 5 afferent bran- 

 chial arteries. The first and last afferent branchials split quite near 

 their origin to supply 2 gills each. On the right side the gills alter- 

 nated with those of the left, the first being situated between the first 

 and second of the left side and so on backwards. The size of the 

 gills was the same as on the other side except that the last was very 

 small, and only about one third the size of the sixth. There were 

 6 afferent branchials on this side, one to each gill, but the last 

 small gill was supplied by a twig from the sixth, given off near the 

 place where it entered the sixth gill. 



Nachdruck verboten. 



Zum Bau und zur Histogenese der menschlichen Samenzellen. 



Von Dr. Wederhake, Elberfeld. 

 Mit 9 Abbildungen. 



Die folgenden Untersuchungen wurden an dem Sperma gesunder 

 Männer im Alter von 23 — 62 Jahren ausgeführt. Ich untersuchte fast 

 ausschließlich Ausstrichpräparate, teils ungefärbt, teils nach Färbung 

 mit Safranin, Methylviolett, Methylgrün, Safranin-Methylgrün, Methylen- 

 blau- van GiESON, Methylenblau- Crocein-Scharlach. Die Untersuchung 

 namentlich der frischen Präparate geschah meistens sofort nach der 



