90 SATURDAY LECTURES. 



divided, cannot be renewed. The idea, therefore, that oyster 

 fishermen, in cuttino; up the star-fish, "make two or three 

 star-fishes out of each captive," is evidently erroneous. This 

 insensibility to mutilation is common to a large number of 

 the lower animals found on the coast. The sea-anemones 

 {Actinozoa) accomplish even that mathematical paradox, 

 multiplication by division; for when they move from one 

 part of a rock to another, they often leave fragments of them- 

 selves behind, and these fragments soon become smooth and 

 spherical, and are transformed to perfect, though minute, 

 anemones. The flat-worms {Eurylepta) offer a still more 

 remarkable instance. When cut to pieces, each piece not 

 only continues moving in the direction in which the whole 

 animal was moving at the time, but gradually becomes com- 

 plete in all its parts — a veritable " chip of the old block." It 

 is related that two polyps often attempt to swallow the same 

 pre}^, and when this is not easily severed the largest polyp 

 gapes and swallows his antagonist. This last seems, how- 

 ever, to be the gainer by the operation, as, after lying in the 

 conqueror's body for an hour or so it issues unhurt and often 

 in possession of the, original bone of contention. 



THE CRAB. 



Next to the 03^ster few animals are more often on the tables 

 of the Washingtonian than the crab, and I will ask you to 

 bear his form in mind — whether as vou have seen him 

 scampering along sidewise on the sand or dished up " dev- 

 iled," or in "soft shell;" while I rapidly trace his develop- 

 ment. The crab undergoes such changes that it has been 

 known by different names at different periods of its growth, 

 and has been placed in distinct orders. The species most 

 used here and southward is known as Callinedes hastatus, but 

 as its early history has not 3^et, so far as I am aware, been 

 critically studied, I will take the common shore crab {Can- 

 cer irroratus) as an example, for it is closely allied to the 

 European table crab. Here we have a picture of the newly- 

 hatched or Zoea form. (Fig. 5.) You will agree with me 

 that in this singular, long-bodied, long-spincd affair there 



