78 THE AQUARIAN NATURALIST. 



floating bodies ; still it was evident, from all observa- 

 tions made in relation to this part of their (Economy, 

 that the progeny derived from these eggs were any- 

 thing but like Medusae, and it has only been by re- 

 searches of a very recent date that satisfactory infor- 

 mation relative to their growth and development has 

 been obtained by competent observers, among whom 

 we select Sir John Dalyell as the exponent of this 

 portion of their history. 



Selecting a specimen of Medusa chrysaora (PI. I. 

 fig. 4) eight inches in diameter, says Sir John Dal- 

 yell, I lodged it in a clear and capacious glass jar on 

 the 24th of August. Herein the umbrella continued 

 to collapse and to reach the surface by impulse on the 

 water, as these animals do naturally in the sea. On 

 gaining this position, the Medusa remained still and 

 motionless, as if to be carried along by the flow or the 

 ebbing of the tide. Nevertheless, although the spe- 

 cimen seemed sufficiently vigorous, it could be kept 

 only a few days from decay. There seems a natural 

 delicacy incident to the whole tribe in confinement ; 

 nor have I been able to preserve any adult individual 

 above a month in activity. 



On the 25th of August, this Medusa being removed 

 from its vessel, a quantity of brownish matter, like 

 dust, remained at the bottom. Subjected to the mi- 

 croscope it proved to consist of a multitude of ani- 

 mated creatures in quick and varied motion, but to 

 the naked eye they were hardly perceptible the 

 merest specks, infinitely minute ; nor by an ordinary 

 lens could their proportions be discovered. 



Higher powers, next resorted to, showed them to 



