PORTUGUESE MANOF-WAB. 



69 



The colony or hydrosome of the Portuguese man-of-war 

 ■consists of long locomotive tentacles, which, when the ani- 

 mal is driven by its broad sail or float before the wind, 

 stretch out in large individuals from thirty to fifty feet. 

 These large Hydra-like zooids are arranged in small groups, 

 arising from a hollow stem com- 

 municating with the chymiferous 

 cavity extending between the in- 

 ner and outer wall of the float. 

 The " feeders " are of two kinds, 

 large and small, and are clustered 

 in branches growing from a com- 

 mon hollow stem, also communi- 

 cating with the chymiferous or 

 body-cavity. L. Agassi z, whose 

 •description of this animal we are 

 condensing, states that he has 

 seen these feeders "gorged with 

 food almost to bursting," but has 

 never seen undigested food in 

 any of the other organs. The 

 medusa-buds (gonophores) arise 

 from a third set of very small 

 Hydras, but form very large clus- 

 ters suspended between the clus- 

 ters of feeders. These reproduc- 

 tive zooids resemble the locomo- 

 tive zooids, but, like the feeders, 

 have no tentacles. The medusa- 

 buds, which are male or female, 

 arise singly, either from the base 

 of the reproductive zooids or 

 from the stems which unite the 

 latter. These buds, as in Tubu- 

 laria, wither without dropping from their parent stock. It 

 ■appears, then, that the floating hydrosome of a Siphon- 

 ophore is like that of the fixed Hydractinia or Coryne, with 

 the addition of locomotive zooids and a float, as seen in 

 PJiysalia, Velella, or the swimming-bells of Halistemma. 



Fig. 49. — Phyealia, or Portuguese 

 mau-of-war.— After Agassiz. 



