'J4 IIEI^URTS Of SOClETlKsS. 



inch. But diffeveiice of pressure is comparatively ineffective to produce any 

 change, as the pressure without is ahvavs exactly counterbalanced by the 

 pressure within. (4) The deep-sea fishes, which are mostly carnivorous, live on 

 smaller fishes ; these a^ain depend for thtur sustenance on the remains of surface 

 forms, which, when dead, sink slowly towards the bottom. They also live on 

 alga; which are similarly sinkiiiK. The stomachs of fishes taken from i,r)iH) fathoms 

 have been found to contain sea-weed. The modifications effected by these con- 

 ditions are of three kinds:— d) In the absence of suu-lisht the colours of the 

 fishes are mostly of a simple kiu<l, as black or silvery ; only in a few cases do we 

 meet with such colours as purple. The eyes are modified in two ways— they 

 either become smaller and disappear, or ai-e f?i-eatly enlarged, or 

 if they remain unchanged the fish is provided in addition with 

 sensitive tactile organs, such as long streaming tentacles, which atone 

 for the want of sufficient vision. But the most remarkable case is 

 where we see the production of accessory visual and light-producing organs. 

 On some species is found a row of accessory eyes, ranged longitudinally down 

 each side of the body, and also on the tail. These consist of parts answering to 

 the cornea, the crystalline lens, the vitreous humour, the retina, and the optic 

 nerve of the human eye, and it is impossible to resist the conclusion that they 

 ai-e eyes capable of seeing. Still more strangely, between them are placed 

 glandular structures secreting a mucus which emits a phosphorescent 

 light. These are really so many small lamps, and thus the animal 

 is a source of light to itself. Very many other marine forms are 

 phosphorescent, and there is in these great depths, no doubt, a magnificent 

 system of submarine lighting. (2.) The skeletons of many deep-sea fishes, when 

 brought to the surface, are excessively spongy, the calcareous matter is wanting, 

 and the muscles are flabby. This appearance, however, may be owing to the 

 rapid change of pressure to which they are subjected when raised from the 

 depths. The minute nuantities of gas contained in the blood and other fluids 

 must expand and rupture the tissues. i3.) At all gi'eat depths the conditions 

 are practically the same all over the world, so that there is nothing to prevent 

 deep-sea fishes from migrating to any part of the deep sea. Accordingly we find 

 that many of them have a wide range, not only over the Atlantic, but also over 

 the Pacific. Uniformity of couditions produces uniformity of distribution. lu 

 the ocean depths there exist no effective barriers like that furnished by a 

 mountain range on the surface of the earth. Mr. W. R. Hughes called attention 

 to the various orders of marine animals in which phosphorescence occurs, instanc- 

 ing especially the phosphorescent light observed by the members of the 

 Marine Excursion to Oban in the Peuuatula which they captured on that occasion. 

 March 14th.— Biological Section- Mr. S. Wilkius exhibited Prunus spinosa 

 (the blackthorn) in bloom, from Dorset ; Mr. Morley exhibited HymenoplujUiuti 

 Wilsoiti, crested, from North Wales, and StigeocIo)iiicin protoisam, from Barut 

 Green ; Mr. Blatch exhibited Leptiisa funiida and Phloeopora corticalis, two 

 species of coleoptera, from Sutton Coldfield, both rare, and new to the district. 

 Mr. K. W. Chase exhibited four specimens of a rare migrant, Plectrophanes 

 lapponica, taken near Brighton. Mr. .1. K. Baguall exhibited liiccia <jlauca from 

 Erdington, also stigmas and pollen of the two forms of Primula vulgaris, show- 

 ing a ditt'erence in character of the long and short styles, and also in the size of 

 the pollen. Mr. W. B. Grove exhibited and described on behalf of Mr. A. W. 

 Wills, who was unavoidably absent, a series of microscopic slides, illustrating 

 the Palmellaceaj, a family of confervoid algae, growing in water or on damp 

 surfaces. March lilst.— Mr. Bolton exhibited a gi-eat number of specimens of the 

 beautiful Eolis Landsburfjii, and other marine organisms, from Bangor. — Mr. 

 ■ Goode read the general report drawn up by himself and Mr. W. P. Jtlarshall, on 

 the dredging operations at Oban in July last. He gave a description of the mode 

 in which the dredging was can-ied on, the apparatus used, which was exhibited, 

 and a list of the dredging stations, together with an abstract of the material 

 obtained at each. The report also contained a number of valuable suggestions 

 for improving the apparatus and the manner of usiug it in future dredging 

 excui'bions, 



