Il6 PROTECTIVE FEATURES IN YOUNG OF VERTEBRATES. 



apparently one penalty for its safety, for it is much incommoded 

 in its progress through the water. Violently lashing its tail it 

 rushes hither and thither, up and down, through the surface 

 water, with its head in its " house " much as a terrified cat with 

 its head in a bag. The jelly so loosely clings to the ascidian that 

 it frequently drops off. 



But the curious protective features in larval vertebrates form a 

 subject so varied and so new that more cannot be attempted in 

 these notes than to point out some of the more salient features 

 which recent researches have made known to us. Amongst the 

 vertebrates we find embryonic structures often resembling in detail 

 the analogous organs in larval invertebrates; nay, even in the 

 vegetable world, in the embryonic stages of plants, and in the 

 young growing parts of adults, corresponding provisions occur. 

 The stipules, the bases of leaves, the more or less broadened 

 proximal part of the petiole, the pedestal of the petiole, scales, 

 spines, hairs, and gummy matter, all subserve the same important 

 protective purposes. Sir John Lubbock, referring to the presence 

 of stipules, declares that the most general reason for their exist- 

 ence seems to be the protection of the young and tender bud, 

 though they may take at times the function of leaves, while they 

 may be spiny for the protection of the whole plant, sometimes 

 glandular, and so on; but their protective function explains their 

 frequent transiency. It is precisely so in the animal kingdom. 

 We see in the highest groups, in quadrupeds, birds, reptiles, 

 amphibians, fishes, and ascidians, examples of the curious care 

 which is exercised in nature to ensure the safety of the tender and 

 otherwise defenceless young. Doubtless the absence of colour in 

 the case of typical pelagic larvae is one of the most remarkable 

 provisions ; but hardly less so is the presence of peculiar colours 

 in other larval as well as adult forms. The late Professor Moseley 

 looked with little less than amazement at the strange colours 

 exhibited by the inhabitants of the gulf-weed in the Sargasso Sea. 

 " The shrimps and crabs which swarm in the weed are," he wrote, 

 "exactly the same shade of yellow as the weed, and have white 

 markings upon their bodies to represent the patches of Membrani- 

 pora. The largest shrimp occurring has a dark-brown colour with 

 sharply defined areas of brilliant white upon its surface, thus 

 closely resembling the older darker-coloured pieces of weed, 



