their Secretions, 627 



remarkable properties, but in the Octopus moschatus it is 

 probably the source of the musky smell, 



** An amber scent of odorous perfume," * 



which that cuttle exhales so strongly as to fill quickly a whole 

 apartment, whether the animal be dead or alive, and whence it 

 derives its specific designation. A native species of Helix (H. 

 alliaria, smells at times strongly of garlic. " When fresh taken," 

 says Dr. Turton, " it diffuses an odour exactly like the smell 

 of garlic, so powerful that two or three of them will scent a 

 room for some hours" {Land and freshwater Shells, p. 56.); 

 and, according to Mr. Sheppard, the collector may frequently 

 be guided to its retreat by this exhalation {Lin. Trans., vol. 

 xiv. p. 160.); so that what Nature doubtless intended as a 

 beneficial gift, will often prove its bane in these evil days. 

 I was once a collector, and have often taken this snail ; but 

 at no time have I perceived the smell, until I had plunged the 

 shell into boiling water ; and even then, according to the 

 experiments of Dr. Johnston, the smell is not always obvious. 

 " Four specimens of equal size," says that gentleman, "and 

 alike in colour, and in the number of their whorls, were 

 taken from beneath one stone. None of them had any smell 

 while alive : but, on immersing them, one by one, in hot 

 water, two emitted a very strong alliaceous smell, in one it 

 was faint, and in the other it was not perceptible. It would 

 appear, therefore, that the animal has the power of retaining 

 or emitting its peculiar odour at pleasure ; and that, in death, 

 its emission may be prevented by accidental circumstances. 

 I could not satisfactorily ascertain its source ; but it appeared 

 to arise from a yellowish fluid, pressed out from above the 

 head." (Edin, Phil. Journ., vol. xix. p. 77.) 



8. A phosphoric fluid is secreted by several mollusca. 

 Linnaeus tells us, on the authority of Bartholinus, that, when 

 the Octopus vulgaris is opened in the dark, a light so strong 

 and splendid is emitted, as perfectly to illuminate the room. 

 {Si/st, Nat., p. 658.; edit, dec.) I am not aware that any 

 gasteropode is phosphorescent; but the Pholades, among 



contained. In the Bulimus ovatus Brug. a little gland, which has not been 

 described, opens into this canal ; it is of the size of a bean, trilobate, 

 granulated, and situated under the oesophagus and the inferior ganglion 

 of the cerebral ring, so that it is surrounded by nervous filaments passing 

 from this ganglion. The distribution of all the ducts may be easily ob- 

 served when filled with mercury : M. Kleaberg names them mucous ducts, 

 but he has not been able to determine their use and importance." {Edin. 

 Journ. Nat. and Geogr. Science^ vol. ii. p. 63.) 



* Bosc maintains that ambergris derives its scent from this cuttle, on 

 which the whale feeds. {Hist. Nat. des Vers, vol. i. p. 48.) 



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