88 



LIFE, IN ITS LOWER FORMS. 



at the good pleasure of the creature projected, and un- 

 folded to a length ten or twelve times that of the body. 

 Each thread is set with a single row of short filaments, at 

 regular distances, which are ordinarily carried in spiral 

 curves, capable of elongation or contraction like the 

 cables themselves. 



The crystalline Cydippe represents the Ciliograde order 

 of Acalephce, or that whose motion is performed by means 

 of ciliary paddles. Another order is the Physograde, where 

 the apparatus for swimming consists of one or many blad- 

 ders inflated with air, probably generated by the animal. 

 An example of this tribe is well-known to those who 

 navigate the warmer regions of the ocean as the Portu- 

 guese man-of-war (Physalia pelagica), where we have seen 

 it in myriads studding the calm surface of the glittering 

 deep. Nor is it wholly a stranger to more northern climes, 

 for fleets of these adventurous craft are sometimes driven 

 by the force of Atlantic currents far out of their reckon- 

 ing, and stranded upon our western shores. 



This singular animal consists of an oblong bladder of 

 clear membrane, surmounted by a thin crest, which runs 

 along its upper edge, and is capable of being contracted, 

 so as to be almost invisible, or of being elevated into a 

 tense and lofty sail. When in the latter condition, the 

 whole forms a beautiful object ; the glossy, colourless 

 bladder reflecting the sun's rays, while the upper half of 

 the sail is tinged with a delicate rose-colour, and the bot- 

 tom of the bladder with a rich azure. Ag the little thing 

 tosses and floats upon the waves it bears a striking resem- 

 blance to a child's toy-ship ; and even those most familiar 

 with its appearance gaze upon it with pleasure. We 



