356 



SCIENTIFIC NEWS. 



[April 13, 1 8 



with all its inhabitants in full activity. At the least 

 alarm the tentacles and partly-protruded body were 

 withdrawn into the opening of the polype, and a 

 minute trap-door closed over them to protect them 

 from injury, each opening being furnished with a 

 tiny operculum, or lid, that was pushed up when 

 the animal protruded itself, and fell back when it retired. 

 As few survived on being transferred to an aquarium, 

 many attempts had been made to kill the animals sud- 

 denly when expanded, so as to mount them as per- 

 manent objects for the microscope. The theory was that 

 if, whilst expanded in sea water, fresh water was 

 suddenly ejected on them they would be killed before 

 they could retreat ; but it was not so easy to put the 

 theory into practice, and failure was far more common 

 than success. With reference to the structure of these 

 animals, the fixed polypes attached to the common 

 body took in the nutriment for its support. Each 

 consisted of a sac with an internal mouth, sur- 

 rounded by tentacles. From the mouth the hollow 

 cavity continued below into, a common channel, 

 traversing all the branches and the main trunk. The 

 tentacles were thread-like appendages, containing the 

 only organs of offence and defence these little creatures 

 possessed. When food was conveyed into the mouth, 

 and digested, it passed into the canal, which traversed 

 the whole colony. The walls of the canal were lined 

 with vibratile cilia, which kept up a continuous current, 

 and thus every part of the structure was supplied with 

 all that was necessary to maintain the vigour of the 

 community. The individual polypes often became 

 absorbed, and in some species there appeared to be a 

 sort of winter res^, but with the return of spring the 

 polypes were produced as plentifully as ever. The 

 fixed or permanent polypes were neuter in sex, and cor- 

 responded to the workers in a beehive. For the 

 multiplication of the species, special buds were set apart, 

 being produced only at certain seasons, and occupying 

 ' different positions in different species. The buds consisted 

 of an outer protective covering, enclosing either a male or 

 female zooid, and these, becoming free, entered upon an 

 independent existence, and presented such a contrast to 

 the original stock, both in shape and habits of life, that it 

 seemed difficult to believe the new animal had any rela- 

 tion to the old. In most cases it assumed the form known 

 to marine zoologists as that of the medusa— a small crystal 

 dome, so delicate that it could only just be distinguished 

 in the water, through which it was propelled by the con- 

 traction of its side, and with a fringe of long tentacles 

 that waved and floated like threads in the liquid element. 

 It would be difficult to exaggerate the beauty of these 

 floating flower-like bubbles, with their vivid tints 

 and graceful outline. To their other charms, that of 

 phosphorescence was often added, and though indi- 

 vidually minute, their numbers were so immense that 

 they played an important part in the luminosity of the 

 ocean. Increase by means of budding, so general in 

 the colony, was by no means absent from the free 

 swimming polypes. It was not unusual when the true 

 reproductive function was arrested or in abeyance for 

 buds to be produced on the structure, most commonly 

 on the lower margin of the swimming bell, and those 

 buds originated free zooids in all respects like the parent 

 from which they sprang. Typically the free swimming 

 polypes were either male or female; but it must not be 

 assumed that all the species produced free swimming 

 polypes, some being fixed. The embryos, which now 



for a short time led a roving existence, had their outer 

 surface covered with vibratile cilia. After a time the 

 body enlarged at one end, and a thin, horny film was 

 formed over a portion of the surface ; its movements 

 slackened, and at length ceased ; the cilia disappeared, 

 and the embryo became attached to the rock by the en- 

 larged end, which flattened out into a disc. This was 

 the first step towards the foundation of a new colony. In 

 the course of time the upper end developed into a fixed 

 polype, enclosed within a capsule with a movable lid, 

 and by a series of successive buddings and branchings a 

 plant-like colony was built up in aU respects resembling 

 the original parent. Growth was comparatively rapid 

 for the size of the little animal concerned in building it — 

 a large specimen of one kind of sertularia being under 

 favourable circumstances formed in the course of fourteen 

 days. 



ZOOLOGICAL SOCIETY. 

 At the monthly general meeting, held on March 22 nd, at 

 the Society's house, in Hanover Square, Dr. E. Hamilton 

 (Vice-President) in the chair, it was stated that amongst 

 the additions to the Society's menagerie during the month 

 of February was a second specimen of Griffith's fox 

 (Cams Grifftthsii), from Bussorah, received on deposit ; 

 four small and very beautiful finches (Erythrura psitlaced), 

 obtained by purchase; and five pheasants (Phosianus 

 principalis), presented by Major Peacock, R.E., of the 

 Afghan Frontier Commission. 



ROYAL HORTICULTURAL SOCIETY. 

 At the last meeting of the Scientific Committee, Dr. 

 Masters reported that the blue daisy exhibited from 

 Tangier at a previous meeting by Dr. Lowe was Bcllis 

 annua. Sir Joseph Hooker mentioned that it was com- 

 mon in the neighbourhood of Tangier, and that it was 

 different from the plant found on the Atlas Mountain 

 {Bellis canilescens). 



Dr. Masters, alluding to the great differences that exist 

 in the species of Pinus as to the time at which the con- 

 stituent scales of the cone separate in order to liberate 

 the seed, showed a series of cones of Pinits insignis, the 

 oldest of which bore the date 1864. In this all the scales 

 were widely separate. The most recent cones dated 

 from 1877, and in them the scales were not at all sepa- 

 rated. Between these two extremes, cones were shown 

 exhibiting almost every intermediate stage of separation. 

 It is to be remarked that the separation begins generally, 

 just above the centre of the pendulous cone on the side 

 furthest away from the branch, at the place where the 

 obliquity of the cone, due to the free exposure to light 

 and air, and the absence of obstacles afforded by the branch 

 was greatest, and that it follows a spiral course towards 

 the base of the cone. The scales separate in successive 

 spiral coils, till, at length, all except a few at the base an i 

 apex respectively, and which are probably sterile, are 

 separated one from the other. 



Dr. Masters also referred to various semi-double and 

 other orchids submitted to him for examination. 



Dr. Masters exhibited a drawing of a magnificent new 

 Anthurium,^. Chantberlaini, which had appeared accident- 

 ally with an importation of Cattleya Gaskelliana, in the 

 garden of the Right Hon. J. Chamberlain. The heart- 

 shaped leaves are of gigantic size, and the large boat- 

 shaped spathe is of the richest crimson colour. 



Mr. T. Christy sent some seeds of Euchresta Horsfieldii 



