ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 35 



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Penis of Drake and Gander.* — A. Trawinski gives an account of 

 the macroscopic and microscopic structure of the penis in these birds, 

 and calls attention to a vestigial representation of a penis in the cock. 



Linnet of Hawaiian Islands.f — Joseph Grhmell discusses "a 

 problem in speciation " in connexion with the Hawaiian representatives 

 of Carpodacm frontalis. This bird was introduced into the Hawaiian 

 islands from California less than forty years ago. 



In all available specimens of the linnet from the United States range 

 the usual colour (in the parts of the plumage which are coloured) of 

 males after the post-juvenal moult, is red. There occur rather in- 

 frequently, irrespective of locality, individuals of three other colours — 

 yellow (most rarely), orange, and red with yellow or orange feathers 

 intermixed. In California the common red type has prevailed for at 

 least sixty years. 



A series of male linnets collected in the Hawaiian islands are all of 

 the yellow or orange type of coloration. The author argues that the 

 peculiarities are not to be considered manifestations of ordinary individual 

 variation, nor as seasonal changes, nor as the result of individual sene- 

 scence. They must be due in some way to change of habitat. 



Evidence is brought forward to eliminate the more obvious environ- 

 mental factors (temperature, humidity, change of food, reduction of 

 enemies). The off-colour character is somehow associated with insularity 

 of habitat, but the prime stimulus is unknown. " A deficiency in 

 capacity, of the germ, for the formation of the appropriate enzyme may 

 have been intensified through close breeding until the condition was 

 reached where the amount of enzyme produced in the feather-anlage is 

 insufficient to carry on oxidation of tyrosin beyond the yellow, or at 

 farthest the orange stage." 



Changes of Plumage in Red Grouse.J — E. A. Wilson has gone 

 carefully into this question, describing and figuring the plumage changes 

 in cock and hen, and the local variations in both. In the cock the two 

 periods, November to June, and June to November, mark the two 

 seasonal changes of plumage. The first is a plumage worn throughout 

 the winter, as well as during the courting and breeding season of the 

 spring. The second is a plumage worn throughout the summer and 

 autumn. In the hen the two changes of the plumage are completed, in 

 the one case by the end of April or the beginning of May, and in the 

 other case by July and August. The actual feather-changes in the cock 

 and the hen are very comparable in character, notwithstanding the 

 discrepancy as to season, the moults being asynchronous by about two 

 months. Very beautiful plates illustrate the paper. 



New Burmese Frog.§ — N. Annan dale describes a new species of 

 frog used as food in Burmah, and hitherto confused with Rana tigrina. 

 The new species R. burkilli, frequents the same localities as R. tigrina, 

 but buries itself in the embankments of rice-fields in dry weather, while 



* Bull. Internat. Acad. Sci. Cracovie (1910) pp. 720-7 (2 pis.), 

 t Univ. California Publications (Zool.) vii. (1911) pp. 175-95. 

 X Proc. Zool. Soc. (1910) pp. 1000-33 (24 pis. and 1 fig.). 

 § Records, Indian Museum, v. (1910) p. 79. 



