206 CRUSTACEANS. 



tected. It is true, however, that certain organs, though diminutive, and 

 apt to be overlooked, are always present as auxiliaries for its security. 

 Yet as it does, appear that, together with the side, it is totally unpro- 

 tected, we may conjecture that the shell occupied by the parent is truly 

 designed as a substitute for an integument, within which this most impor- 

 tant portion of the animal substance can be withdrawn. While still im- 

 mature, the spawn is a dense mass of beautiful purple ova, afterwards 

 fading, as it relaxes and ripens towards maturity. Plate LIII. figs. 3, 4 ; 

 cluster enlarged, fig. 5. 



This spawn consists of several hundred ova or capsules ; but they 

 are not alike numerous as those of most of the preceding animals. The 

 numbers may partly depend on the age of the parent. Small quantities 

 are borne by small specimens ; those resembling fig. 6, whose limbs do 

 not expand an inch ; nor do the numbers of capsules belonging to many 

 large specimens exceed an hundred. The capsular integuments are gra- 

 dually refined, so as to expose the included foetus rolled up, with the 

 head and tail in contact. As it advances, two large black eyes, like 

 crescents, appear externally in front, and an internal red spot about the 

 middle of the body. At length, escaping their prison, the young animals 

 appear as in figs. 5, 7, 8. 



But, in conformity with the general normal crustacean shape, these 

 young animals bear no resemblance to the parent, which must be gained 

 on passing through the various metamorphoses appointed by nature. 



Now, it would seem much more like a lobster than a crab. It is at 

 first very light and transparent the upper portion disproportionately 

 large compared with the rest of the body. Only four limbs are visible, 

 while a few segments indicate the lower or fleshy half, terminating in a 

 broadened extremity of about eleven irregular bristles. 



At this time the creature swims with a jerking action. But never 

 surviving beyond a few days, the observer attempting to follow its pro- 

 gress permanently, will be disappointed. 



April is the chief breeding season, when the spawn appears in per- 

 fection, adhering constantly to the female ; for it is never deposited on 

 foreign substances, whether the parent be large or small. 



