242 



THE OCEAN WOELD. 



The nursing polyps have been called poboscidiferous organs by 

 Mr. Milne Edwards, who has studied them carefully. They are 

 rendered conspicuous- at a glance by the bright-red colour of their 

 digestive cavity and their extreme dilatability. At the base of their 



stems the very delicate fila- 

 ments called fishing-lines are 

 attached, which are furnished 

 with a multitude of stinging 

 tendrils of a reddish colour. 

 These tendrils slightly re- 

 semble those of the Agalmse, 

 and the sabre-like weapons 

 are not wanting. 



Between the nursing po- 

 lyps are placed in pairs the 

 reproductive individuals, hav- 

 ing the form of an elongated 

 tube very dilatable, and closed 

 at the free end. They have, 

 then, no mouth ! Milne 

 Ed wards calls these " vesicular 

 appendages," and M. Koelliker, 

 tentacles. The buds arranged 

 at the base of each prolific 

 individual vary ; but, accord- 

 ing to M. Yogt, they are al- 

 ways there in pairs a male 

 and female at the base of 

 each stem. Figs. 99 and 100 

 represent the colony we have endeavoured to describe, 99 being the 

 nursing individual of Apolemia contorta magnified twelve times, 100 

 representing the reproductive pair under the same magnifying power. 



Fig. 99. Apolemia contorta, 

 magnified 12 times. 



Fig. 100. Apolemia con- 

 torta, reproductive 

 pair, magnified 12 times. 



THE DIPHYD^E. 



We have seen that the Physophora, the Agalma, and the Apolemia 

 have for the use of the colony a vast number of swimming vesicles 



