200 EVENINGS AT THE MICROSCOPE. 



single eye is separated into two, which are large and 

 attached to the outer arms of two bent processes placed 

 within the body, in the form of the letters UU. The 

 legs are increased by the addition of two pairs, and 

 these are doubly bent in a zig-zag form, and can be 

 protruded from between the valves. 



It is a highly curious fact that the infant Barnacle has 

 thus passed through two distinct types of animal life, 

 those of the Cyclops and the Cypris. These are not one 

 type in different stages, as might be reasonably presumed. 

 The young of Daphnia and of Cyclops are so much alike, 

 that it would be natural to presume the young of Cypris 

 to be of the same form ; in which case, we should have 

 in the young Barnacle merely the first and second stages 

 of Cypris. But it is not so. Cypris does not pass 

 through the Cyclops form at all ; for, according to 

 Jurine, the young when hatched have the appearance of 

 the perfect animal, though varying a little in the shape 

 of their shells. 



It is in this second form, which may be considered the 

 pupa of the Barnacle, that the animal quits its free, roving 

 life, and becomes a fixture for the remainder of its days. 

 And this is a most wonderful process: so wonderful, that 

 it would be utterly incredible, but that the researches of 

 Mr. Darwin have proved it incontestably to be the means 

 by which the wisdom of God has ordained that the little 

 Water-flea should be transformed into a stony Acorn 

 Barnacle. 



Having selected a suitable place for fixing its re.-idence, 

 such as those massive rocks which sustain the impetuous 

 billows on our sea-worn coasts, the great projecting 

 antenna? manifest a new and unprecedented function. 

 Glands situated at their base secrete a tenacious <:lue, 

 which, being poured out in great profusion, cements the 

 whole front of the head to the rock, including and con- 

 cealing the antennae themselves. The cement rapidly 



