Apeil 3, 1903.] 



SCIENCE. 



529 



power for good may be in proportion to 

 these great resources is the prayer of thou- 

 sands of alunmi, whose pride in its past 

 is their hope for its future. 



Thomas M. Deown. 



IiEHIGH UNIVERSITT, 



South Bethlehem, Pa. 



AMERICAN SOCIETY OF ZOOLOCISTS. II. 

 An Experimental Study of the Spawning 

 Behavior of Lampetra wilderi: Jacob 

 Eeighaed, University of Michigan. 

 An attempt was made to extend Gage's 

 excellent account of the spawning behavior 

 of the brook lamprey, as given in the 

 'Wilder Quarter Century' book. Space 

 does not permit more than a statement of 

 results, which were obtained under the 

 auspices of the U. S. Fish Commission: 



1. Fish were numbered and a record kept 

 of their movements and the behavior of fish 

 removed from the nest and then released 

 was observed, but no constant relation was 

 found betiueen individual fish and indi- 

 vidual nests. 



2. The location of nests is determined 

 not by the form or character of the bottom, 

 but by the existence beneath or in the 

 midst of the running water of small masses 

 of water at rest, such as occur in depres- 

 sions of the bottom or behind or in front 

 of obstructions in the stream. Small glass 

 plates set on edge across the stream on a 

 perfectly level bottom have such inert 

 masses of water above and below them and, 

 although the plates are invisible, the lam- 

 preys build nests above and below them, 

 and this on any sort of bottom in which 

 there are stones large enough to serve them 

 for attachment. 



3. Sex recognition appears to be a reac- 

 tion of the male to a reaction of the female. 

 Males, females with eggs and spent females 

 were marked so as to be readily distinguish- 

 able. Attached males when seized by other 

 males at dnce release their hold and the two 



fish separate. Spent females seized when 

 attached behave like males. Females con- 

 taining eggs, if seized by males while at- 

 tached, retain their hold and begin at once 

 to 'shake.' The male reacts to this move- 

 ment by throwing his tail in a loop about 

 the body of the female and then 'shaking' 

 with her. The shaking consists in a rapid 

 vibration of all the body behind the bran- 

 chial region. 



4. The loop formed by the tail of the 

 male is always thrown accurately into the 

 notch between the first and second dorsals 

 of the female. In the female at the breed- 

 ing season, but not in the male, the second 

 dorsal is oedematous and is believed to 

 serve as a support for the tail of the male 

 during spawning. The small anal fin 

 found in the breeding female, but not in 

 the male, may have the same function. 



Some Experiments on the Growth of 

 Oysters: Otto C. Glasek, Johns Hop- 

 kins University. (Introduced by Cas- 

 well Grave.) 



The occurrence of elongated oysters on 

 the edges of marshes and reefs in waters 

 supporting profitable beds is a well-known 

 but puzzling fact to the culturalist who 

 sees such different results imder similar 

 conditions. 



Among the explanations given by other 

 workers, excessive crowding seemed to the 

 author to be the only one borne out by his 

 observations, but to test this view more 

 carefully a number of experiments were 

 made. 



In one, young normal oysters were sub- 

 jected by imbedding in cement to lateral 

 pressure, and exhibited after thirty days 

 a slight elongation, and the scolloped an- 

 terior edges common in elongated oysters. 

 In another experiment, to find if oysters 

 liberated from an oppressive environment 

 would change in shape under other condi- 

 tions, it was discovered that, after forty- 



