Limits of Incubation; Number* of Eggs. 239 



abdominal eggs, found at the end of the year. These, we 

 apprehend, are the advance breeders of the beginning of 

 following year. As spring arrives, younger females, bearing 

 fewer eggs, seem to ripen in a shorter time. They form the 

 bulk of the maximum spawning season, and the few later 

 breeders succeed in due course. 



From another point of view it may be assumed that the 

 Brown Shrimp has but a single long ripe spawning season the 

 first six or eight months of the year. The few late summer 

 breeders are overlapped by those seniors which begin to bear 

 abdominal eggs in autumn and carry them throughout the 

 winter season. Thus does it come about that the Brown Shrimp 

 appears as if actively breeding throughout the entire year ; 

 whereas there are several months of its cessation. Meanwhile 

 the egg-bearers or incubators give a defective semblance of 

 continuity of brood. 



Buckland remarks that the shrimp has comparatively a 

 small number of eggs a few hundreds only. Whereas Herd- 

 man mentions about 5,000 in a fully mature shrimp. We 

 counted the eggs deposited on the abdomen in several Brown 

 Shrimps. Among them in one 2 inches long there were in round 

 numbers 300 ; in a second specimen of 2| inches some 850 ; and 

 in a third = 2| inches long, about 3,550 eggs.* In each case 

 there were some ovarian eggs not yet extruded. What looks 

 like a discrepancy of statement, therefore, rectifies itself, 

 for the older and bigger the shrimp, so is the plenitude 

 of its spawn. This equally applies to crabs and lobsters. 

 The newly extruded eggs are translucent, by degrees 

 assuming a faint amber tinge, ultimately becoming opaque and 

 gradually darkening as they advance in ripeness. They are 

 attached to the abdominal segments and swimmerets by a 

 gluey- like secretion. Here they are freely bathed and 

 oxygenated by the sea water while incubation goes on. 



* In pood-sized females Ehrenbaum has calculated the presence of 4,000 abdominal 

 eggs ; and ho suggests some shrimps may breed twice a year, and thus produce from 

 O.OJO to 7,000 eggs annually. We have grave doubts of the shrimp's ripening its eggs 

 and producing young twice within twelve months. Doubtless the same shrimp rmiy 

 carry two separate batches of eggs on the abdomen in the same year; but only one 

 set of these hatches out young during the twelve months. 



