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K. S. LASHLEY 



ation. The individual AlA must be looked upon either as a 

 mutant or as, more probably, a polyp of another clone introduced 

 by accident into the culture.^ It seems to be hereditarily differ- 

 ent both from Clone D and from the remainder of Clone A. 



Diverse races which can be recognized at a glance are extremely 

 rare in the populations near Baltimore. Several times fifty 



Fig. 8 Diagram of the size relations of two clones kept under similar con- 

 ditions, L and F. From camera sketches of individuals of estimated average 

 size. 



or more clones have been started with polyps from different 

 localities but only twice have distinct races appeared which were 

 recognizable within a few generations. The first of these were 

 Clones A and D. In August, 1913, a small polyp was found which 

 produced very small buds. At first it seemed unhealthy but the 

 buds increased in size and began to multiply rapidly. Un- 

 fortunately the culture could not be continued and the clone was 



* The opportunit}^ for contamination was given by the use of Elodea stalks 

 in these cultures, as in the early part of the experiment no certain method of free- 

 ing them from foreign Hydras had been devised. 



