Sept. 1, 1SG9.] 



HARDWICKE'S SCIENCE-GOSSIP. 



197 



The most striking peculiarity of this creature's 

 appearance, contrasted with those previously de- 

 scribed, is due to the two pairs of antennae being 

 nearly equal in length, the superior being rather 

 the longer : the illustration shows her of the natural 

 size, three-quarters of an inch. The juveniles fish 

 out these Gammaridce by the hundred, and take 

 them home to be boiled for tea, believing them (as 

 greater people have oftentimes done) to be shrimps. 

 Ignorance is in this case undoubtedly bliss, and they 

 are eaten with as much relish as though they were 

 veritable Grangonidee. 



Fig. 142. Gammarus locusta and her brood. 



By the way, 1 have rarely seen true shrimps in the 

 markets hereabouts : the three varieties of prawns — 

 viz., Paleemon serratus, with a long saw rostrum 

 curving upwards, with its anterior half smooth on 

 the upper side, and with seven to eight teeth on 

 the rest of its extent, and five to six teeth on 

 the under side ; Palamon squilla, with a much 

 shorter and nearly straight saw dentated to the 

 end ; and the very much smaller Paleemon varians, 

 with a very short saw, with four to six teeth 

 above, and only two or three below — are all 

 sold here, if below a certain size, under the name 

 of shrimps. 



The rostrum is an unmistakable badge of the 

 Prawn ; moreover, its first pair of feet are slender 

 and terminated by a small didactylous hand ; while 

 the Shrimp proper {Crangon vulgaris) has no rostrum 

 at all, and the first pair of feet are thick, and ter- 

 minated by a monodactylous sub-cheliform hand. 

 It is not advisable to attempt to enlighten a lady 

 vendor of crustaceans, if she should persist in calling 

 her prawns shrimps. Experte credo . "What! you 

 want to tell me them be pra'ans an' not shrimps ? 

 Yive-an'-varty year this blessed Michaelmas have 

 me an' my old man travelled the country wi' 'em, 

 and now for you to tell me as we don't know t'other 

 from which ! ! " 



Another dip, and up comes a brownish semitrans- 

 parent creature something like a washed-out wood- 



louse : this (fig. 143) is Spharoma serratum, a natatory 

 Isopod, with horizontal swimming-plates on the last 

 pair of false feet. Like his terres- 

 trial representative, he can and 

 does occasionally roll himself up 

 in a ball. 



But we must hurry on ; we may 

 not even stop to think of the 

 polypes, and polyzoa, the tunicata, 

 the cirripeds, the diatoms, and a ^'erratum, "x^" 

 hundred other things that pass 

 through our hands in the short space of one hour. 



And now that we have reached home, let us ex- 

 amine this rich-looking bunch of sea-grapes. If we 

 placed them in a dessert-dish, garnished with vine- 

 leaves, we might easily deceive the unwary. These 

 are the eggs of the common Cuttlefish (the pro- 

 prietor of the cuttle-bones on the beach), Sepia offici- 

 nalis. Each one of these was deposited separately, 

 and attached by its pedicle to the stalk of a sea- 

 weed ; others were added one by one till the cluster 

 was completed. (Science-Gossip, 1867, fig. 211.) 

 A cross section of one of these, made when it is 

 new laid (fig. Ill) displays («) the horny exterior 

 covering, (b) the smooth chorion, (c) the curiously 

 folded vitelline membrane, containing (d) the 

 watery-looking yolk. The latter, instead of being 

 connected with the alimentary canal in the usual 

 way (as in birds), is attached, or rather the embryo 

 is attached, to it by the head, by a tube which 

 passes between the cephalic arms, and commu- 

 nicates with the pharynx — " adhceret ovo Sepia 

 parte suo priori" a fact observed and recorded by 

 Aristotle. 



Fig. 144. Transverse Section 

 of Ovum of S. ojficinali*. 



Fig. 145. Vertical Section of 

 Embryo of S. officinalis. 



In fig. 115, a shows the arms or tentacles, b 

 the yolk communicating with the pharynx by the 

 tube (c), and d the funnel or infundibulum, by 

 which the water is expired. At this season most of 

 the fry are upon the point of being hatched; it is in- 

 teresting to detach one of the eggs, and, holding it 

 by its pedicle, to slit the coverings down to the free 

 end with a pair of fine-pointed scissors ; allow the 

 fluids to escape, then turn the bag inside out, and 

 behold a little shapeless, motionless, gelatinous 

 mass. Let this drop with a gentle splash into a basin 

 of clean sea-water, and, hi ! presto ! what a trans- 

 formation ! In a moment the little quivering lump of 

 colourless jelly turns spotted brown, unfolds, darts 



