i8o 



HARDWICKE'S SCIENCE-GOSSIP. 



" What about your fruit?" methinks I hear some 

 reader ask. Let me at once frankly admit that my 

 pets help me to get rid of it — it is, however, little 

 enough they take, if I except standard cherries, nor 

 do I begrudge them their share, when they contriljute 

 so largely to my enjoyment ; but, of course, I take 

 proper precautions to preserve it in the shape of 

 cotton stretched from bush to bush, which affords 

 ample protection, and, being almost invisible, is no 

 disfigurement to the garden. 



Edward H. Robertson. 



OUR BRITISH MARINE ANNELIDA. 

 By Dr. P. Q. Keegan. 



AN unobtrusive tribe of animals, of an annular 

 conformation and bilateral symmetry, of no 

 great dimensions, rather sluggish in habit, and of a 

 structure sometimes singularly beautiful, yet in itself 



transverse constrictions into membranous rings, 

 which frequently develop lateral rudimentary limbs 

 usually provided with locomotive organs called setce 

 (bristles and hooks) ; there is also frequently a 

 distinct "head," and, in some instances, auxiliary 

 branchial organs called " elytra '' are distributed over 

 the back. The nervous system consists of a chain 

 of ganglia extending throughout the length of the body 

 and connected by longitudinal and transverse bands 

 of varying lengths ; the eyes are very simple, con- 

 sisting of " an expansion of the extremity of the optic 

 nerve imliedded in pigment, and provided occasion- 

 ally with transparent spheroids or cones ; " the ears 

 have sometimes many otoliths ; the digestive ap- 

 paratus extends the whole length of the body, being 

 straight (except in Pectinaria, &c., where it is 

 convoluted, and in Polynoe, Aphrodita, and Sigalion, 

 where long sacs or processes are developed on each 

 side thereof) ; there is, except in the tube-building 

 species, a muscular proboscis armed with strong teeth 

 and knobs ; the functions of a liver are discharged by 



Fig. 104. — Sea'mouse {Aphrodite aculeatd). 





Fig. xoii.—Serpula contortuplkata. 



Fig. 105. — Sigalian boa. 



delicate and fragile and needing the shelter of a shell, 

 &c. A very remarkable tribe of creatures, mostly 

 tenants of the profound depths of the ocean ; yet 

 some prefer the quietude of the seashore or the oozy 

 slime of the matted sea-plants. Some are denizens 

 of chambers hollowed in the soft yielding deserts of 

 sand between tide-levels ; others tunnel through the 

 water-penetrated sandstone rocks of the seaboard of 

 an inland tidal harbour. Many of them roam and 

 prowl about, free, naked, and unattached, in search 

 of prey or in wantonness of animal activity; others 

 are sedentary, and move in the restricted sphere of a 

 shell or habitation permanently affixed to a rock, 

 loose stone, or a sea-post. Nearly the whole tribe 

 are embellished with beautiful colouring, and exhibit 

 microscopic structures of extreme loveliness and un- 

 paralleled constructive ingenuity. 



Such are the principal features of the Annelida — a 

 class of animals which stand on an equal rank with 

 the crabs, lobsters, &c. Generally speaking, they 

 may be characterised as having elongated, rounded, 

 segmented bodies, often divided by many superficial 



glands opening into the digestive canal, and a sort ©f 

 renal organ (the segmental organs) has been observed 

 in some instances. The gills vary much in develop- 

 ment, sometimes they are not specialised, while in 

 other species large and exquisite organs are distinctly 

 referable to aeration. Between the walls of the body 

 and the stomach a corpusculated fluid moves to and 

 fro, while special close trunks or canals with varying 

 branches spread over the body, contain what has been 

 denominated the " blood proper," or the " pseud- 

 hremal system." 



A child wandering by the seashore is attracted by 

 a variety of interesting marine objects cast up from 

 the deep by the ever-chiding waves. He muses over 

 these forms, he gathers and closely inspects them. 

 We ourselves remember being specially attracted in 

 this manner by the curious aspect of a series of white 

 convoluted tubes investing the surface of various sea- 

 pebbles, old shells, &c. These tubes are tenantless 

 habitations of a curious and interesting sea-worm of 

 the genus Serpula. Several species of this genus are 

 found on our shores. Sometimes we observe two or 



