io8 Dwellers of the Sea and Shore 



subject to considerable variation, and may range from 

 a few hours to several weeks. 



As was indicated, the mother attaches her eggs to 

 the hairs of her abdominal appendages. Here they 

 hang suspendeci like clusters of miniature grapes. 

 The number of units in a cluster is not large, averaging 

 perhaps not more than three hundred. Indeed, this 

 number is surprisingly small when one considers the 

 enormous broods of some other crustaceans. The 

 blue crab, for instance, will produce in a single spawn- 

 ing 1,750,000 eggs. However, as the female hermit 

 crab gets older her fecundity increases, but the incre- 

 ment is not enough materially to change the average 

 given above. Her eggs are a deep cherry red in color, 

 and in size no larger than the period ending this sen- 

 tence. Each one is suspended in a membranous sac 

 which in turn is attached by a short thread to a bristle 

 on one of the forementioned appendages. Receiving 

 no other care than an occasional brushing to keep them 

 free from particles of dirt, they are carried for a fort- 

 night before they are ready to hatch. 



But in the meanwhile some remarkable changes have 

 been taking place. By tearing apart, under the dis- 

 secting microscope, an egg which is but a day old, the 

 differentiation of organization can be seen making 

 its first appearance. That mysterious transformation, 

 due to those unfathomed forces that cause the cells of 

 all organic structures to assume their predetermined 

 arrangement, has just taken place. Nearly a week 

 later, examination of one of the spherical units will 

 show that the yolk comprises nearly half of its bulk; 

 while in the remainder of the egg content can be traced 



