6 54 



THE POPULAR SCIENCE MONTHLY. 



Physalia, the Portuguese man-of-war, with its beautiful blue 

 float, may at times be seen on all sides. The float, filled with air, 

 serves to keep the animal on the surface, and, driven by the wind, 

 to bear it from place to place. It is a curious animal, or rather 

 cluster of animals we should say, for naturalists now consider it 

 to be a group of individuals, having different functions, but 

 working for the same general cause — that of supporting the mass. 

 They say that in this group there are some whose sole purpose is 

 to obtain food, some to digest, others to reproduce, etc., yet each 

 is an individual animal working for the good of the whole, that 



the whole may work for its good, and 

 that in conjunction they may perform 

 all the functions of life necessary to the 

 well-being and general welfare of the 

 whole united colony. The cluster has 

 most remarkable defensive powers, be- 

 ing well furnished with lasso cells or 

 stinging organs. These consist of little 

 barbed, arrow -like points, fastened to 

 thread-like arms, each of which is coiled 

 up in a little cell. Whenever it is neces- 

 sary to use them they are hurled out with 

 violence, and each barb, striking the ob- 

 ject, penetrates, for it has the power of 

 " working into " flesh, and, being covered 

 with a sort of poison, it in conjunction 

 with many others benumbs the prey and 

 renders it harmless. That the Physalia 

 possesses this property to a marked de- 

 gree, some of the sailors of the Albatross 

 can testify, for they incautiously placed 

 their hands in a tub of water containing 

 one, and the shock they received was 

 compared in violence to a strong shock 

 from a Ley den jar. Sea-anemones pos- 

 sess this same property, although the 

 common shore species can affect only 

 very tender animals. I have seen a deep- 

 sea anemone, six inches in length, by this means kill and afterward 

 swallow a lively fish a foot long, that was placed in the aquarium 

 with it. The fish barely touched the anemone, then seemed incapa- 

 ble of moving farther, and after a few struggles became paralyzed. 

 These arrow-points possess the power of motion for several hours 

 after being detached from the animal. Lasso cells can be replaced 

 when lost, and in a very short time. On a square foot there are 

 millions of cells. It is a curious fact that all well-defended animals 



— POKTCGTTESE MaN-OF-WAB 



(.Physalia arethusa). 



