GENERAL REMARKS ON THE EGGS OF MARINE FISHES. 27 



that a curious parallel to this is found in the group of jointed 

 animals; in these we find that the more lowly organised 

 aquatic shelled crabs and lobsters grow throughout life and 

 have continually and periodically to throw off their hard shells 

 because they become too small for them, whereas the more 

 highly organised land insects and spiders have no such troubles 

 to contend with, but accomplish all their growth in an ado- 

 lescent period before the sexual organs become mature. 



