SCIENCE-GOSSIP. 



H7 



" mucous adhesiveness " to be now referred to ; 

 it is only suited for transportal over short 

 distances. 



5. By becoming adhesive in the wet state. Whilst 

 experimenting during the last four years on the 

 buoyancy of the seeds of a large number of British 

 plants, I noticed in certain cases that they became 

 invested, whilst in fresh and sea-water, with a 

 greater or less amount of mucus. Such seeds or 

 seed-like fruits when removed from the water and 

 placed on a feather or on paper, stick as firmly as 

 if gum had been employed. Whilst conducting 

 similar experiments Mr. Darwin recorded this 

 curious feature in the cases of the seeds of Lepidium 

 sativum and Linum usitatissimiim in sea-water (Journ. 

 Linn. Soc. Bot. i., 130, also his " Life and Letters," 

 ii., 54, and " Gardeners' Chronicle," May 26, 1855) ; 

 but he did not regard it in the light of an aid to 

 dispersal. Out of about seventy species of plants 

 that I specially tested as likely to produce mucus 

 in water, nine exhibited this quality in a marked 

 degree, viz., Capsclla bursa-pastoris, Viola tricolor, 

 Matricaria chamomilla, Salvia verbenaca, Nepeta 

 glechoma, Prunella vulgaris, Plantago major, P. 

 lanceolata and Luzula campestris. Prolonged 

 drying does not diminish this capacity of forming 

 mucus in water. With six species immersion in 

 water merely produced a " stickiness," which, 

 however, enabled the seeds to adhere on drying to 

 feathers ; they were, Thymus sp., Lamium purpureum 

 (occasionally), [uncus communis, J. glaucus, 

 J. bufonius and J. squarrosus. 



The facts elicited in my experiments may be re- 

 garded from different standpoints. In the first place, 

 most of the nine plants exhibiting " mucous adhesive- 

 ness ' ' are widely spread, and some of them are cosmo- 

 politan in their range ; but there are many plants 

 as widely distributed and similar in habit, that do 

 not display it, such as Sagina procumbens, Ccrastium 

 vulgatum, Stellar ia media, Spergula arvensis, etc. 

 Amongst the plants of other orders, the seeds of 

 which did not become mucous in water, were 

 Draba vema, Reseda luleola, Viola canina, Poly gala 

 vulgaris, Alchemilla arvensis, Saxifraga granulata, 

 S. tridactylites, Veronica agrestis, V. arvensis, and 

 several others. Then again, we note that these 

 nine plants are for the most part plants of the 

 roadside, the waste ground and the meadow. As 

 far as my experiments go, those of the brook, the 

 marsh, and of the edges of ponds and rivers, do not 

 exhibit mucosity when their seeds are placed in 

 water, although several of them occur over a large 

 portion of the globe and some in the isolated islands 

 of the Southern Ocean ; they are Nasturtium 

 officinale, N. amphibium, Cardamine hirsuta, Viola 

 palustris, Stellaria aquatica, Montia fontana, Peplis 

 portula, Hydrocotyle vulgaris, Hottonia palustris, 

 Scrophularia aquatica, Callitrichc aquatica, A) undo 

 phragmites, etc. 



It is also to be remarked that this peculiarity 

 seems to be more frequent with Labiate than with 

 Caryophyllaceous plants ; in the first case it 

 characterised three out of sixteen species examined, 

 in the last none out of nine. The three Labiate 

 plants that exhibited mucosity are referred to above, 

 those that failed to respond to the test were Lycopus 

 europaus, Mentha aquatica, Nepeta cataria, Scutellaria 

 galericulata, Stachys betonica, S. sylvatica, S. palustris, 

 Ballota nigra, Lamium album, Teucrium scorodonia, 

 and Ajuga reptans ; nor can Lamium purpureum and 

 the species of Thymus be said at present to possess 

 this feature, though their nucules sometimes became 

 adhesive in water. Finally, this property appears 

 to be somewhat capricious with different species of 

 the same genus. It was found in Nepeta glechoma, 

 but not in N. cataria, in Viola tricolor, but not in 

 V . palustris and V. canina. 



6, Fairfield West, Kingston-on-Thames ; August, 1894. 



LORD SALISBURY AND 

 EVOLUTION. 



LORD SALISBURY'S Presidential Address to 

 the British Association probably came as a 

 surprise to those who only know his lordship as a 

 politician. Though it was not marked by any of 

 those features which have made the addresses of 

 some of his predecessors famous, it will probably 

 cause a considerable flutter in certain circles, for 

 Lord Salisbury has shown himself in science, as in 

 politics, a reactionary. The most important part 

 of the address was the conclusion, in which the 

 President dealt with the problem of the origin and 

 cause of life. He dwelt on the conflict between 

 mathematicians and biologists, as to the length of 

 time required for the earth to cool sufficiently to 

 allow the process of evolution from the jelly-fish to 

 man, and proceeded to discuss Weismann's recent 

 attitude to the theory of natural selection. "To 

 the riddles which nature propounds to us," says 

 Lord Salisbury, " the profession of ignorance must 

 constantly be our only reasonable answer. The 

 cloud of impenetrable mystery hangs over the 

 development, and still more over the origin, of life. 

 If we strain our eyes to pierce it, with the foregone 

 conclusion that some solution is and must be 

 attainable, we shall only mistake for discoveries 

 the figments of our own imagination." There is 

 little doubt that to those to whom the writings of 

 our foremost scientific men are unknown, owing 

 to the unattractive language in which they 

 are written, Lord Salisbury's address, from so 

 authoritative a pulpit as the chair of the British 

 Association, will be regarded as having seriously 

 damaged the case for Evolution. As a con- 

 temporary points out, the popular knowledge of 

 the verifying evidence that has been accumulating 

 since the publication of " The Origin of Species," 

 is very slight. " The writings of many of the 

 staunchest adherents of Evolution have been 

 couched in such technical, and at times in such 

 uncouth language, that they could not possibly be 

 understood, except by those who have had a 

 long training in the special subject." 



