200 
IOWA ACADEMY OF SCIENCE Voi.. XXVIII, 1921 
who in connection with his work in the U. S. Bureau of Fisheries 
and the U. S. Department of Public Health has shipped literally 
hundreds of thousands of these fish, tells me that his experience 
also points to a greater male death-rate in transit. It may, then, 
be safely concluded that in general the 'female Gambusia survive 
shipment better than the males. 
LITERATURE CITED 
Barney, R. L. and Anson, B. J. (1921) Seasonal abundance of the 
mosquito destroying top-minnow, Gambusia a ffinis, specially in relation to 
male frequency. Ecology, Vol. II, No. 1, pp. 53-69 (Jan.). 
The Zooloo^^l Laboratory 
The Johns Hopkins University 
