NATURAL HISTORY 



41 



In 1950, orders had to be kept over until they could be filled, owing 

 to scarcity of animals. In 1951, 7,000 were brought in, from Menemsha 

 Bight; 3,000 were returned to the sea as too small for laboratory use. 

 In 1952, 11,000 were brought in from Fisher's Island on 7 trips. The 

 supply in 1953, 1954 and 1955 was adequate. 



The value of the Arbacia supplied may be judged by the fact that 

 they sell for $ 13 a hundred at the Biological Supply House. As an 

 interesting comparison, about 63,700 lbs. of lobster were brought in 

 by local fishermen from the Woods Hole area in 1949; this is approxi- 

 mately 56,000 lobsters. In 1950 there were 44,500 lbs. or 39,000 lob- 

 sters. One lobster averages i 1/8 lbs. (Data kindly supplied by Homer 

 P. Smith, business manager of the M.B.L.). A lobster sells for $ .80 at 

 Woods Hole, or $ 80 a hundred. 



The cause of the decreasing quantities o^ Arbacia around Woods Hole 

 is not known. Depth bombing during the war years has been suggested, 

 and also the increase in numbers of starfish, their especial enemy. The 

 scarcity may be due to climatic conditions, such as hard winters and 

 the two recent hurricanes (1938, 1944). But it seems probable that it 

 has been caused by over-collecting; most animals which are system- 

 atically taken for food or wearing apparel, e.g., lobsters, birds, seals, 

 are protected by law in some way to prevent their extinction. Arbacia 

 are not protected. Also the quantities oi Arbacia needed for the newer 

 chemical investigations of eggs and sperm are enormous in comparison 

 with the few needed in the past, for morphological or even for physio- 

 logical work. 



Arbacia have been recorded as scarce several times previously. A 

 survey was made by the U. S. Bureau of Fisheries in 1874 (Verrill and 

 Smith), and again in 1902 (H. L. Clark) of the region around Woods 



