142 



NA TURE 



[December 8, 1892 



often much more strongly developed and the creatures them- 

 selves much larger than the fresh- water forms, and the manipu- 

 lation is therefore somewhat more difficult. The marine forms 

 are also more apt to be incrusted with foreign bodies, bored by 

 predatory sponges, like Ciiona, or even by other mollusks, or 

 perforated by certain annelids which have the power to dis- 

 solve the lime of which the shell is composed, and in this way 

 secure a retreat for themselves. 



Shells which do not contain the living animal are frequently 

 occupied by hermit crabs or by tubicolous annelids. The latter 

 fill up the larger part of the spire with consolidated sand or 

 mud, in the centre of which they have their burrow. The 

 hermit crabs do not add anything to the shells which they 

 occupy, but, on the contrary, by their constant motion are apt 

 to wear away the axis or pillar of the shell, so that often a 

 specimen of this sort may be very fairly preserved and yet on 

 the pillar show characters entirely different from those which 

 one would discover in a specimen which had never been occu- 

 pied by a crab. A shell which the crab has selected for its 

 home is often taken possession of, as far as the outside is con- 

 cerned, by a hydractinia, a sort of polype, which produces a 

 horny or chitinous covering which is very difficult to remove 

 from the shell to which it is attached. As the hydractinia grows 

 it finally covers the whole shell, to some extent assumes its 

 form, and then, if the creature has not attained its full growth, 

 this is apt to take place around the edges of the aperture, which 

 are continued by a sort of leathery prolongation which assumes 

 in a rough way the form of a shell. The crab, when he grows 

 too large for the shell in which he has ensconced himself, is 

 usually obliged to abandon it and find a larger one, which is 

 always a difficult and more or less dangerous operation ; but if 

 his shell is overgrown by the polype referred to, it often happens 

 that the polype and the crab grow at about an equal rate, so 

 that the latter finds himself protected and does not have to 

 make a change. It is supposed that the polype profits to some 

 extent by the microscopic animals attracted by the food or ex- 

 crement of the crab, so that this joint housekeeping is mutually 

 beneficial, and, for such cases, since the word parasite would 

 jiot be strictly accurate, the word commensal has been adopted. 

 These modified shells often assume very singular shapes. The 

 polype is able in the course of time to entirely dissolve the 

 original calcareous shell upon which its growth began, so that 

 if the spire be cut through it would be found throughout of a 

 horny or chitinous nature. Some of the older naturalists were 

 deceived by forms of this sort and applied name^ to them, sup- ■ 

 posing that they were really molluscan shells of a very peculiar 

 sort. 



In removing the animal matter from the shell of large gas- 

 tropods it will often require a good deal of time and care to get 

 out all the animal matter from the spire, but it is well worth 

 while to take the trouble, as the presence of such matter forms a 

 constant attraction for museum pests of all descriptions. A 

 medium-sized syringe is convenient for washing out the spire of 

 such shells. The ordinary marine gastropods may be treated in 

 a general way like the fresh-water gastropods. There are, 

 however, abnormal forms, especially among tropical species, 

 which require particular attention. Some species become 

 affixed to corals and overgrown by them, retaining only a small 

 aperture through which the sea water can reach the prisoner. 

 Such specimens are best exhibited by retaining a part of the 

 coral and cutting the rest away, showing at once the mode of 

 occurrence and the form of the covered shell. Borers are 

 always more difficult to handle and prepare for the cabinet 

 than other mollusks. They are usually more or less modified 

 for their peculiar mode of life, and frequently rely upon their 

 burrow as a protection, so that the shell is reduced, relatively 

 to the animal, to a very small size. Most of these forms are 

 best kept in alcohol. The hard parts may properly be repre- 

 sented in the cabinet by other specimens. Some of the bivalves, 

 such as the American "soft clam," possess very long siphons, 

 covered with a horny epidermis, and it becomes a question as 

 to whether an attempt should be made to preserve this epider- 

 mis in the cabinet or not. The writer has seen very nicely 

 prepared specimens in which the fleshy portions had all been 

 taken out and replaced by cotton, so that the epidermis of the 

 siphon retained its original position and form ; but such speci- 

 mens are always very delicate, easily broken, and liable to 

 attack by insects, so that it would seem hardly worth while to 

 go to the trouble, when specimens may be preserved complete 

 In alcohol showing all the features referred to. Boring shell- 



fish, like Pholas, frequently have accessory pieces, which are 

 liable to be lost when the soft parts are removed unless care is 

 taken to avoid it. Other bivalves have the internal ligament 

 reinforced by a shelly plate, which is called the ossiculum. 

 This is very easily detached and lost, and, being an object of 

 great interest, special pains should be taken to preserve it, 

 even if it should become detached. 



JAPANESE CAMPHOR. 

 T^HE United States Consul at Osaka^gives in a recent report 

 the following particulars, reprinted from the November 

 nnmher of the Board 0/ Trade /ournal, respecting the Japanese 

 camphor trade : — 



The camphor tree, from which the resinous gum is distilled, 

 is a species of the laurel, and is found in the provinces of Tosa, 

 Hiuga, and Satsuma, in the south of Japan. Large groves of 

 the trees are owned by the Japanese Government, the wood 

 being very desirable for shipbuilding. The districts in which 

 the camphor tree is found are mountainous and situated far from 

 the sea. No reliable information can be obtained as to the cost 

 of producing the gum before being transported in junks to Hiogo. 

 The peasants who engage in distilling the roots and branches of 

 the trees are said to be poor, and employ the rudest machinery. 



The market value of crude camphor gum and of oil of camphor 

 per picul (133^ lbs.) during the past year was as follows: — 

 Drained, 38-25 dols. : wet, 37 00 dols. ; old dry, 43*50 dols. ; 

 average, 36 "50 dols. ; camphor oil, 5-25 dols. ^ 



The highest and lowest prices during the same period were as 

 follows : — Highest, 4000 dols. ; lowest, 33*00 dols. 



Camphor gum is exported in tubs measuring about 6| cubic 

 feet ; oil in kerosene tins and cases. The grades are from old 

 dry down to new wet, and the various grades depend upon the 

 quantity of adulteration. In oil there are two grades — white and 

 brown. 



Adulteration is practised for the most part by adding water 

 and oil just as far as the buyer will tolerate. In some cases 

 20 lbs. of water will run out of a tub in twelve hours. The 

 unadulterated article, known as the good old dry, can some- 

 times be bought. The only system of tests in determining value 

 of the different qualities is by burning and by absolute spirit. The 

 percentage of pure camphor which the crude yields when refined 

 varies according to the quality of the crude. The average per- 

 centage of gum produced from the wood as compared with the 

 original weight of the wood cannot be accurately ascertained 

 here, the only foreigner known to have visited the camphor dis- 

 tricts having declined to furnish any information on the subject. 

 The total exports of camphor from Hiogo during 1891 in 

 catties of I ^, lbs. each amounted to 3,850,400 catties consigned 

 to the following destinations : Europe (countries not specified), 

 1,777.300 catties; London, 335,600 catties; Germany, 

 209,200 catties; United States, 1,277,000 catties; China, 

 5 1,900 catties ; France, 199,400 catties. 



As regards the manufacture of camphor the following par- 

 ticulars are extracted from a report by the United States Consul 

 at Nagasaki. 



Camphor is found alike on high elevations and in the valleys 

 and lowlands. It is a hardy, vigorous, long-lived tree, and 

 flourishes in all situations. 



Many of these trees attain an enormous size. There are a 

 number in the vicinity of Nagasaki which measure 10 and 12 ft. 

 in diameter. The ancient temple of Osuwa, at Nagasaki, is 

 situated in a magnificent grove of many hundred grand old 

 camphor trees, which are of great age and size, and are still 

 beautiful and vigorous. It is stated that there are trees at other 

 places in Kiu Shiu measuring as much as 20 ft. in diameter. 

 The body or trunk of the tree usually runs up 20 and 30 ft. without 

 limbs, then branching out in all directions, forming a well- 

 proportioned, beautiful tree, ever green and very ornamental. 



The leaf is small, elliptical in shape, slightly serrated, and of 

 a vivid dark-green colour all the year round, except for a week 

 or two in the early spring, when the young leaves are of a 

 delicate, tender green. The seeds or berries grow in clusters 

 and resemble black currants in size and appearance. The ^ood 

 is used for many purposes, its fine grain rendering it especially 

 valuable for cabinet-work, while it is used also for shipbuilding. 

 The roots make excellent knees for ships. 



In the manufacture of camphor the tree is necessarily 

 destroyed, but, by a stringent law of the land, another is planted 



NO. 1206, VOL. 47] 



