June 1, 1869.] 



HARDWICKE'S SCIENCE-GOSSIP. 



127 



PREHENSILE ANTENNA OF THE 

 ENTOMOSTRACA. 



By Major. Holland, R.M.L.I. 



IN Science-Gossip for July, 1865, we Lave an 

 illustrated paper on Cyclops quadricomis : in 

 the July number for 1866 we get one on the 

 Baphniadee, profusely illustrated; and the October 

 number of 186S gives us an interesting sketch of 

 the heart of B. Bulex. These collectively contain so 

 much information concerning the several families of 

 this subdivision of the Crustacea, that one has to 

 be careful to avoid repetition. 



In the summer every ditch and pool supplies us 

 with water-fleas in myriads ; and even the dwellers 

 in large cities, who never wander" by meadow, lake, 

 and stream," but love the fair face of Nature none 

 the less, because the exigences of stern duty shut 

 it off from them, may enjoy an hour's fishing with a 

 pipette in their water-jugs with good sport if their 

 main comes from the reservoir of an old- 

 established company; in Devonshire I could 

 always make sure of three varieties of Daphnia iu 

 the carafe in my dressing-room. Like many other 

 very common things, they are very beautiful and 

 very wonderful : perhaps nothing sends the embryo 

 microscopist into such a fever of enthusiasm as the 

 first good view of one of these tiny creatures, with 

 throbbing heart, moving eyes, palpitating flanks, 

 and nacreous reticulated shell flashing rainbow 

 hues, as it gasps and struggles in the small drop of 

 liquid on the slide. Like all other animals, they 

 present us with evidences of design, showing us 

 special adaptations of certain parts or organs— the 

 enlargement of this, the modification of that, to 

 meet some new requirement of the creature's life- 

 conditions, or the non-development beyond a rudi- 

 ment, or total suppression of some element of the 

 original type of the order, which would have been 

 superfluous, perhaps harmful to the being, in the 

 particular province allotted to it. 



In the Baphniadee the first pair of feet of the 

 male differ considerably from the corresponding 

 limbs of the female, being furnished in the former 

 with a strong claw or hook attached to the 

 extremity of the second joint, which enables them 

 to seize and hold fast any object; and it seems that 

 the gentleman Daphnia would not be able to get on 

 at all without this arrangement; for the lady 

 Daphnia is a coquette. " Sighing and singing of 

 midnight strains " won't do for her ; " deeds not 

 words " is her maxim ; respectful admiration from 

 a distance is all very well for some people, but she 

 will never requite a passion so coolly controlled ; 

 she prefers audacity; at first she affects alarm 

 mingled with indignation, and leads her inamorato 

 a fine dance if he is silly enough to allow himself 

 to be discouraged by her seeming reluctance ; she 



demands a judicious amount of rightly-timed gentle 

 violence, and when her suitor, in a moment of 

 happy inspiration, boldly seizes her hand, or, to be 

 more precise, catches her first pair of feet with the 

 armed first pair he is furnished with for the 

 purpose, she ceases to say nay, and welcomes his 

 wooings with the warmest sympathy. 



But coquetry is not confined to fresh water ; 

 there is flirting in the briny ocean, and the love- 

 chase goes on swimmingly even in brackish rivers 

 and estuaries ; everywhere living things dance to 

 the good old tune of " C'est V amour, V amour, 

 I'amour." In salt, or half salt and half fresh 

 cruising-grounds, the gallant knights of Biaptomus 

 Castor, of Anomalocera, and other distinguished 

 orders, who would be Benedicts, must chase and 

 catch their fast-dashing brides like the wild 

 Tartars of the Steppes ; and as to the old love 

 game of " catch me, kiss me," there is added " and 

 keep me if you cany They are provided (instead 

 of armed feet) with hinge-jointed antennae, with 

 -which when they have caught they can hold fast 

 the aggravating damsels. 



The fair Cyclopida must be superlatively flighty, 

 they literally require to be assailed right and left, 

 and Nature, like a good kind mother, ever meeting 

 the need of her children, and determined never to 

 spoil sport, has provided their cavaliers with hinge- 

 joints in both of their antennae ; though one such 

 weapon is found to meet the requirements of most 

 genera. This enlargement in the right or in both 

 antennae renders the male distinguishable at a 

 glance. The ocean swarms with these curious 

 Branchiopoda, whose cast-off cases and exuviae form 

 no inconsiderable portion of the muddy ooze of the 

 deep-sea beds. Somebody mentions that he has 

 seen a Daphnia moult no fewer than eight times in 

 seventeen days : what a heap of " old clo " there 

 must be to be worked up into new fabrics of some 

 sort, out of the exploded suits of Entomostracans 

 alone. 



Fig. 92. Female of Labidocera magna, nat. size. 

 Fig. 93. Male of Labidocera magna, nat. size. 



Here we have a pair of Pelagic Entomostracans 

 taken by the towing-net in the South-west Pacific. 

 I can find no record of the capture of this species 

 on our own coasts, but I suspect that it is to be 

 found in the waters of the warm current that 

 tempers the climate of our western shores. The 



