Marvels of the Universe 



557 



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length of as much as six inches, to reach its food, while the always moving tentacles create a current 

 and bring in a constant supply of minute organisms for the voracious appetite.* The Acorn Barnacle, 

 on the other hand, is stationary ; and though he curl and uncurl his feathery fingers in the manner 

 sho\\-n on page 556, he is unable to obtain so extensive a commissariat, and has to await the arrival 

 of his prey instead of being carried out to " pastures new." Yet the Acorn Barnacle has adapted 

 himself to and flourishes in his surroundings ; every rock and post beyond high-water mark is covered 

 \\ith his kin. Many an unwary bather, when he has attempted to scramble on to some likely rocks, 

 knows to his cost how numerous is the company of this species and how sharp are their shells. 



Another point of interest in the Barnacle is that both sexes are contained in the same individual, 

 so that each one can reproduce its kind. But Nature has further provided for the continuity and 

 \'igour of the species by means of external influence. Just as some plants whose ordinary flowers 

 possess the power of 

 fertilizing themselves 

 are provided with 

 other flowers which 

 require pollinating 

 from other individuals 

 in order to invigorate 

 the strain, so Bar- 

 nacles are provided 

 with complemental 

 males which introduce 

 fresh vitaJity, and so 

 minimize any of the 

 evil tendencies of 

 heredity. These males 

 are extremely minute 

 — about the size of 

 a pin's head — and 

 attach themselves to 

 the shield of the 

 Barnacle. 



There are many 

 different species, both 

 of Stalked and Acorn 

 Barnacles, and they 

 show a great variety 



both as regards the attachment tube and the shells of the shield. The best known variety of the 

 former class is the Ship Barnacle. Another species, which is found in Australian seas, has the 

 tube about three-quarters of an inch long, covered with fine, silky brown hairs, while the shells 

 are as pointed as the claws of a mole ; in fact, its general appearance is that of a brown mole's 

 foot. In another the tube is covered with horny scales, while a third has the tube fine, flexible and 

 semi-transparent, marked with white dots. It has the appearance of a snake's skin, and the shells 

 of its shield are shghtly pink. Its beauty justifies its title of " the Elegant Barnacle." The largest 

 of the Stalked Barnacles is the Giant, of which a fine specimen has a shield of about three and a 

 half inches in length, with a thick, scaly tube. In colour it is a dirty ivory. 



Amongst the Acorn Barnacles there are several deserving of notice. The largest is the Parrot, 

 a denizen of the South American seas, with purplish-pink shells, which attain a girth of between 



* This may account for the higher development and the greater average size of the Stalked Barnacle. 



Flioto hul 



[E. J. SjiUta'.F.It.M.S. 



THE TEETH OF THE LEECH. 



The tenacity of the Leech is proverbial, and its bite is performed by a complex arrange- 

 ment of circular saws, one of which is here shown. {It is greatly nnagnified.) 



