to whether or not the lobster of the northern hemisphere lays 

 her eggs only once in two years, and, while it is still not abso- 

 lutely accepted, there seems to be very conclusive evidence 

 that this is so. In the case of the crawfish, our experiments 

 seem to indicate that this may take place every year ; but it 

 is to be noted that none of the females had eggs in one year 

 (1909). It may be, therefore, that the frequency of spawning 

 is more than once in two years and yet less than every year. 



With regard to the time ^oj casting of shell of the male, among 

 the specimens (from Table Bay) kept in the tanks, this was in 

 October and September. 



The rate of growth or age of the Cape Crawfish is a matter 

 which has not yet been investigated. Judging from the 

 experiments at the Marine Station, St. James, the increase in 

 size is not rapid and is unequal. In the case of Female A it 

 was 1-5 mm. in 1907, the same in 1908, but 6 mm. in 1909 

 /the year in which no eggs were laid), and 2 mm. in 1910. 



4. Geogr./^phical Distribution of Cape Crawfish. 



The Cape Crawfish has a peculiar distribution, being confined 

 to the West Coast so far, at least, as practical fishery purposes 

 are concerned. A few were found as far East as Bird Islands, 

 on the East Coast, during the trawhng operations of the Pieter 

 Faure. These were, however, of a small size, though specifi- 

 cally identical with the crawfish found so abundantly near 

 Cape Town. Its place is taken in Natal by other and quite 

 different kinds, which occur in no great abundance, chiefly 

 amongst the rocks of the shore. It is found also at Hermanns, 

 the specimens got at this locality being also of a small size. 

 In False Bay it is occasionally met with, but so seldom that its 

 capture is somewhat of a rarity. On rounding Cape Point 

 and coming into the colder waters of the Atlantic it is found 

 in great abundance, as for instance at the Kommetje, only 

 a few miles from False Bay. From this point northwards it 

 is very plentiful. How far north it extends has not been 

 recorded, but it was found in abundance by the Pieter Faure 

 as far north as Mercury Island. 



Doubtless the distribution is determined directly or in- 

 directly by the great difference in the character of the water 

 of the West Coast northwards of Cape Point from that of 

 the East and South Coast, the former, originating in the 

 Antarctic Circle, being of a much lower temperature and 

 specific gravity than the latter, which comes from the tropical 

 regions of the Indian Ocean, and is of a higher temperature 

 .and specific giavitv. This distribution is not peculiar to the 



[C.P. 5-'i3-] 



