THE OYSTER-INDUSTRY. 227 



of starfish can readily be distinj^aished by tlieir difference in coloring; all those having a bluish tint being 

 invariably females, while a reddish or reddish brown color indicates a male. " When cut open, so as to expose the 

 genital organs, the difl'ereuce between the males and females is still more striking. The long grape-like clusters 

 of reproductive organs, extending from the angle of the arms, on both sides of the amlnilacral system, to the 

 extremity of the rays, present very marked diflerenees in the two sexes. The ovaries are bright orange, while 

 the spermaries are of a dull cream color. At the time of spawning • • * the genital organs are distended to 

 the utmost, tilling completely the whole cavity of the ray ; the abactiual system [i. e., the sides and back of the rays] 

 being greatly expanded by the extraordinary development of these organs." 



The two species common on' the New England coast are Asterias arenicola and Asferia.s t^iilparis, and, though much 

 alike otherwise, they have different times of spawning, the former (Massachusetts bay to Florida) throwing out its 

 eggs a fortnight or more earlier in the summer than the latter, whose range is more northerly and hence in colder 

 waters. Their period of spawning, also, is very short, comprising only three or four days. The eggs produced by 

 the females, as well as the spermatozoa sent out by the males, find exit Irom the body through five very small holes 

 in a series of large plates on the back at the angles of the arms. Such eggs as are fortunate enough to meet with 

 spermatozoa in the water, before being overtaken by some form of destruction, are fertilized, and immediately begin 

 a very curious series of changes in embryonic growth, which have been fully described by Alexander Agassiz. 

 This embryolog is like that of no other group of animals, but may be roughly compared to the transformations of a 

 butterfly in the chrysalis. The larva which hatches fi-om the starfish's egg is entirely nulike its parent, in form or 

 structure, being an oddly shaped, ragged, transparent little creature, permeated through and through by water- 

 tubes. This larva, when perfected, is called a brachiolaria, and swims around for several days by means of vibrating 

 cilia, which keep it whirling and bobbing about, not choosing its course, nevertheless, by an exertion of its will, 

 but a i)rey to all the chance breezes and currents that can get it in their power. 



These larvpe, says Mr. Agassiz, are to be found floating in large numbers at night, though never by day, near 

 the surface among cast off skins of barnacles, which furnish them with food during the time when they swim freely 

 about, in company with multitudes of small Crustacea, annelids and hydroids. At such a time they are fit food 

 for shellfish, and no doubt many fall into those ti-eacherous small currents that lead into an oyster's, clam's, or 

 mussel's mouth. This hel^js to even up the account which the adult starfishes are making, iu their dailj- onslaughts 

 upon the mollusks. 



The jaunty, free career of the brachiolaria, however, is soon over. Changes, begun before they were understood, 

 now begin to alarm him. He is losing his shape and assuming a strangely symmetrical, five-armed form, covered 

 with soft spines and tentacles. Before he knows it, and without the loss of a single portion, the bactolaria, by 

 absorption, has lost himself in the body of a true young starfish, and finds himself slowly acquiring the stiff armor 

 and dignified mien which marks his approach to an adult condition. He ceases his gay wanderings and sinks to 

 the bottom, or crawls upon the frond of some floating sea weed. This occurs when he is about three weeks old. 

 But now that he is no longer an embryo, but a real baby starfish, his growth is very slow. Mr. Agassiz says that 

 by arranging the starfishes, big and little, found upon our rocks into series according to size, we may roughly 

 estimate the number of years required by them to attain their full development; this he presumes to be about 

 fourteen years. During the earlier years the growth is more rapid, of course, than later. One young specimen, 

 kept in an aquarium at the Cambridge museum, doubled its diameter in five months. That they begin to spawn 

 when six or seven years old, or hardly half-grown, is ascertained ; but as to how long they may live after that, 

 provided the dangers of the sea are escaped, we have no information that I am aware of. 



The size to which they attain varies in different species. The rare British Urastcr glacialis, Ag., has been 

 seen 33 inches iu diameter, and some even larger than this have been reported from near Eastport, Maine, where 

 echinoderms abound in greater number, perhaps, than anywhere else on our coast. South of Cape Cod, however, 

 it is rare to see one measuring more than ten inches across, and the great majority do not exceed six. 



The destructiveness of these creatures has long been recognized by naturalists and fishermen alike. In Bishop 

 Sprat's History of the Royal Society of London, we are told that manj' jears ago the Admiralty Court of England 

 laid penalties on those eugaged in the oyster-fishery " who do not tread under their feet, or throw upon the 

 shore, a fish which they call fice-Jingcr, resembling a spur-rowel, because that fish gets into the oysters when 

 they gap and sucks them out". Numerous accounts might be given of instances when great damage had been 

 done the shellfibheries, particularly along the Welsh and Cornish coasts, by starfishes, in a very short time. 

 Oysters, not only, but clams and scallops of every sort, fall a prey to some of the many sjnny raiders, whose size 

 or habit of living in deep or shallow water, fits them to attack one or another sort of mollusk. Couch notes, in 

 his Cornish FaiDia, the large Uraster rttbens, which is called clam or cramp iu Cornwall, and occurs there in 

 multitudes in spring, infests the fishermen's crab-pots, to steal the baits; and a Belfast man reports that he had 

 had starfish frequently seize his lug-worm bait and be brought up on his hook while fishing. Mollusks, then, are 

 not their only food. The carrion of the sea is eaten by them with voracity, and iu this respect they are beneficial 

 to us and the rest of animal life. 



I do Tiot jiropose to give a history of British starfishes, but before leaving them, niust tell one or two 



