XXXVI 



MEMOIR ON PHYSALIA 



Linn. Soc. Proc, vol. ii., 1855,//. 3-5 



The specimens of Physalia on which Mr. Huxley's observations 

 "were made, were collected on board the Rattlesnake, between the 

 25th of February and the 3rd of March, between lat. 25° and ij" S. 

 and long. 5° and f W. They varied in size from \ in. to 2 in. in the 

 long diameter of the float. The author first describes the general 

 appearance of the specimens, of which he doubts whether the largest 

 were adult, and then proceeds to a minute examination of their de- 

 tails, dividing them for this purpose into the float or air-bladder, and 

 the appendages of greater or less length which depend from it when 

 the animal is in its natural position at the surface of the water. The 

 smaller specimens he states to be the best adapted for examination. 



The float is described as consisting of an outer coat, an inner coat 

 and an air-sac contained within them, attached only to one spot of 

 their parietes, and there communicating with the exterior by a small 

 ■constricted aperture, which was always found on the upper surface. 

 The disposition of the appendages is very irregular, but the larger 

 tentacles are generally placed more externally, the smaller and nascent 

 organs more towards the centre. These appendages are of three 

 kinds, and consist of stomachal sacs, tentacles and cyathiform bodies. 

 Of each of these the author gives a detailed description in their more 

 perfect form, as well as in their undeveloped state as nascent organs ; 

 and then proceeds to inquire, first, what is the physiological import- 

 ance of the organs described, and secondly, what zoological place 

 should be occupied by an animal provided with such organs so 

 disposed. 



Each of these questions the author treats at considerable length. 



