200 EVENINGS AT THE MICROSCOPE. 



which project from the shell. The 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 U U . 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 residence, 

 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 glue, 

 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 



