124 



SCIENCE-GOSSIP. 



[June] J 866. 



CORALLINES AND ACALEPHS. 



IN the No. S of Science Gossip for August, 1S65, 

 Mr. Eife gives us a very pleasing sketcli of the 

 elegant little brandling corallines, sea-mosses, or 

 whichever we may choose to adopt of the various 

 names which have been given to the Polyzoan Zoo- 

 phytes. Among the Tubularias (pipe corallines), 

 Sertularias and Plumularias are perhaps the best 

 known and most striking favourites. These have 

 been popularly quoted as "nameless tribes, half- 

 plant, half-animal, rooted and slumbering through a 

 dream of life ! " Now, the later researches of natu- 

 rabsts — such as the Norwegian observers, Sars, van 

 Beneden, Steenstrup, and many others — sufficiently 

 prove that, so far from slumbering through their 

 appointed cycle, they really lead a most active and 

 varied life ; at one stage of their existence skimming 

 the expanse of ocean as perfect radiated animals, 

 clothed in masses of translucent jelly, which refracts 

 the most gorgeous colours, and even in many species 

 giving out phosphorescent lights ; in others throw- 

 ing out long thread-like tentacles, and exercising 

 their power of stinging severely the hand that dares 

 to meddle with them tQ arrest their course. 



"Who," exclaims M. de Quatrefages (in his fasci- 

 nating history of his researches, conjointly with M. 

 Milne Edwards, on the coasts of Sicily), "who 

 would not declare that a miracle had come to pass, 

 if he saw a reptile emerge from the egg dropped by 

 a hen in his poultry-yard, and the reptile give birth 

 to an indefinite progeny of fishes or birds ?" This, 

 of course, is an exaggerated supposition of a totally 

 impossible occurrence, and yet the generations of 

 the Medusae, and their connection with the Hydroid 

 Corallines, are fully as marvellous, and until tho- 

 roughly investigated might appear quite as incre- 

 dible. In the very interesting " Sea-side Studies " 

 just published in America by E. and A. Agassiz, we 

 have a figure and description of a huge umbrella- 

 shaped jelly-fish {Cyanea Arctica of Agassiz), of 

 which the disk measured seven feet diameter, and 

 the very numerous tentacles, of about fifty-two feet 

 long, issuing in eight distinct bundles from lobes 

 of the disk floating around, and thus covering a 

 space of nearly 112 feet. Strange to say, this 

 gigantic " Discophore" is produced from a "Hy- 

 droid" measuring not more than half an inch in 

 height when full grown, and which in its Hydroid 

 (or Coralloid) state has been named Strobila, and its 

 changes carefully watched. The history of any one 

 ■egg laid by one of these Discophore Medusae in the 

 autumn has been indeed as yet but partially followed, 

 yet sufficiently so to show us that the young 

 hatched from the egg is at first spherical, but pre- 

 sently becomes pear-shaped and attaches itself to 

 the ground. But few of the Mcduseans produced 

 from Hydroid stocks attain this gigantic size ; yet the 



type of their transformations differs but little, and 

 their numbers must be indeed " myriads on myriads 

 peopling every wave." 



These are single specimens of Plumeria falcata 

 (the sickle coralline), or Sertularia argentea (the 

 squirrel's-tail coralline) on which the family "may 

 consist of from eighty to one hundred thousand 

 individual Polypes seated on one stem — a rate of 

 population which, says Dr. G. Johnson, not London, 

 not Pekin can rival ! I do not, however, think it is 

 the opinion of naturalist-investigators that each and 

 all of these Polyp-buds actually become " Medzisean 

 Acalepks" which seems to be the most accepted 

 scientific term for jelly-fishes or sea-blubbers; 

 many of the buds wither and drop off from their 

 stems, others shed their seed to spring up again as 

 Corallines; the Laomedia (sea-thread coralline of 

 Johnston and Landsborough) develops Medusae, 

 which remain always attached to the stem, so far as 

 is yet known, and die when they have laid their 

 eggs. Among the Sertulareans the free and adult 



Fig. 115. a. La/aea dumosa, natural size. b. Polyp cells of 

 the same. c. Young Sertularian Medusa, from Lafoea. 



Medusa is only as yet known as proceeding from 

 one species, Lafaa of Lamouroux, Comularia rugosa 

 of Dr. J. E. Gray, or Sertularia of Johnston, who 

 gives an enlarged figure of the Polypes. Eorbes 

 says of it, It is the most active Polype of its tribe I 

 ever saw, starting up and down in its cell like one 

 of the Ascidioids." Does this action show instinc- 

 tive impatience for freedom ? Of those more 

 vigorous Polyp-flowers (let us call them) that grow 

 and thrive, there seems to be a probability that some 

 contain ovarian vesicles only, and others the ferti- 

 lizing spores, somewhat analogous to the female 

 germ or stigma and the male pollen-cells ol plants, 

 and that here the movements of the waves and 

 currents take the place of the winds and insects, 

 which, among the flowers of the earth, convey the 

 fertilizing influences to the " Ovaria," and that 

 possibly only those Polyp-cells thus perfected swell 

 and in due time float away from the Polypidom to 

 which they have hitherto been fixed ; then increase 

 in size, put forth tentacles, more or less according 



