THE MUSEUM. 



hope the series of articles we shall 

 present, will be the means of their 

 more extended study. 



Barnacles- 



"If you wish to see these little fish- 

 ermen casting their nets," says Mar-' 

 garet W. Leighton in Popular Science, 

 "go to a rocky tide-pool, or to the 

 piles that support some old wharf, and 

 there search for clusters of white cone- 

 shaped shells, from a quarter to a half 

 inch in height. As the tide flows over 

 them, watch carefully and you will see 

 an exquisite little fan of daintily curled 

 feathers slowly emerging from the top 

 of a cone. Soon others will appear, 

 and before Jong the feather fan will all 

 be curling and uncurling. They seem 

 to be scooping up the water and let- 

 ting it run through the fine meshes of 

 the nets, for such really are the little 

 fans, which are sometimes called 

 'glass hands.' 



"The group in which the barnacles 

 belong is named, from this peculiarity, 

 Cirripedia (curled feet). The life his- 

 tory of this barnacle is very wonder- 

 ful. It belongs to the great class 

 Crustacea and is cousin to the crabs, 

 shrimps and crayfish, although at 'the 

 first glance it does not seem to resem- 

 ble them in any particular. If we 

 spend considerable time in watching 

 the barnacles we may be fortunate 

 enough to see one throw out a cloud 

 which thickens the water. If we ex- 

 amine a bit of this under the micro- 

 scope we see it is composed of myriads 

 of living creatures, all moving as fast 

 as possible, flopping their legs and 

 jerking themselves about. Each has 

 a shield-shaped covering for its body, 

 which ends in a long, slender tail. It 

 has six legs fringed on one edge, which 

 it uses for swimming. It it were 

 placed upon the ground it could not 

 take a step, even with its six legs, for 

 they are absolutely useless out of wa- 

 ter. It has one large black eye and 

 on its forehead grows a pair of crook- 

 ed horns. In this stage it looks very 

 much like a young crab or shrimp. 



"It spends its time swimming about 

 with a jerking motion. After passing 

 through several changes, it appears 

 with a shell similar to that of the clam. 

 Its one eye has now divided into two, 

 aud each is affixed to the end of a lit- 

 tle stalk. Nature, thinking perhaps 

 that six legs were not enough, now 

 bestows upon the baby barnacle an- 

 other pair. It soon tires of this stage 

 of its existence, and decides that it is 

 time to fix upon a permanent spot for 

 its home. It generally decides upon a 

 rock, the bottom of a ship, the skin of 

 a shark or the piles beneath a wharf. 



"As soon as it has made its choice, 

 the barnacle fixes itself firmly to its 

 home by a kind of glue which it has se- 

 creted in glands at the base of its anten- 

 nae. When its head has become secure- 

 ly glued to the rock or wood it changes 

 its skin for the last time, casting off 

 with it the shell and the eyes on the 

 stalks. Its swimming legs have be- 

 come transformed into the fishing net. 

 In the first stage the barnacle had a 

 shelly covering in one piece; after a 

 time it donned a shell with two halves 

 like the clam's, and in this last stage 

 its shell is composed of many pieces. 

 It now lives in a beautiful little white 

 castle built of stony plates, leaning 

 towards each other. Just inside the 

 top of the castle there are two of these 

 plates which fit together and form a 

 compact roof. The enemy who storms 

 this fort will have a long seige before 

 he gains an entrance. 



' 'It is. from between the plates at the 

 top of the cone that the fishing net is 

 thrust forth, and all the time that the 

 tide is high it is busy scooping up wa- 

 ter, from which it strains out the tiny 

 animals for food. The net is com- 

 posed of twenty-four delicately curled 

 filaments surrounding the mouth 

 (many-jointed and covered with hairs 

 which are organs of touch). When a 

 tiny living creature comes in contact 

 with these sensitive hairs they immed- 

 iately close tightly over it and carry it 

 towards the mouth, which thrusts it- 

 self out to meet the coming dainty. 



