738 THE AMERICAN NATURALIST [Vol. XLIV 



This year an attempt was made to remove all the 

 spawn of A. punctatum from the special pools. In the 

 middle of June larvae 30-35 mm. long were collected 

 from them and examined as to this pattern ; it was found 

 in but 35 per cent. Two causes may have contributed 

 to this — the abundance of brush in the pools may have 

 caused some spawn of A. punctatum to be overlooked, 

 and the great expansion of the chromatophores— much 

 greater than ever attained in the laboratory, the pools 

 being very dark, probably disguised it in some cases. 

 It was found impossible to put these larvae under ob- 

 servation in the laboratory to test this point, for owing 

 to the long journey or to the change of water they in- 

 variably died within a few hours. 



Little importance would have been attached to a point 

 of coloration so variable as this had it not been found to 

 be uniformly lacking in similar larvae of A. punctatum, 

 whether raised in the laboratory or taken from the pools 

 known to contain little, if any, spawn of A. jefferson- 

 ianum. In view of the range of coloration for A. tigri- 

 num as larvae (indicated by Powers), the degree of con- 

 stancy noted is perhaps the most that could be expected. 



Papers Cited 



Powers, J. H., 1907. Morphological Variation and its causes in Amblystoma 



tigrinum. Univ. of Nebraska Studies, Vol. 7, No. 3. 

 Smith, Bertram G., 1907. The Breeding Habits of Amblystoma punctatum. 



Wright, Albert IT., 1908. Notes on the Breeding Habits of Amblystoma 



punctatum. Biol. Bull, Vol. 14, pp. 284-289. 

 Wright, Albert H., and Allen, Arthur H., 1909. The Early Breeding Habits 



of Amblystoma punctatum. Amer. Nat., Vol. 43, pp. 687-692. 



