42 



HARDWICKE'S SCIENCE-GOSSIP. 



were scattered over the inaccessible face of the 

 cliffs, quite safe from the most ardent botanist. 

 Edging the rocks beyond this were many others, 

 and again it occurred not far from the sea-wall. As 

 this little rarity is spread over so wide a space, and 

 its appearance being somewhat insignificant, there 

 seems little danger of its extinction. — E. Wheeler, 

 Bristol. 



Arabis~stricta (S.-G., 1873, p. 2).— This plant 

 is* happily not extinct on St. Vincent's Rocks, 

 Bristol. (See Journal of Botany, 1872, p. 266; and 

 Science-Gossip, 1872, p. 232.)— /araes Britten. 



Botanical Labels. — We have received a series 

 of botanical labels for labelling Herbaria, adapted 

 to the names in the London Catalogue of Plants, 

 and the manuals of Professor Babington and Dr. 

 Hooker, with extra labels for all new species and 

 varieties recorded in the recent volumes of the 

 Journal of Botany and the Exchange Club reports. 

 It forms a volume of nearly 300 leaves, clearly 

 printed on one side only. The compiler is Mr. 

 Jolin E. Robson, and the publisher Hardwicke, 

 Piccadilly. We have carefully looked the volume 

 over, and think highly of Mr. Robson's industry. 

 Collectors cannot do better than avail themselves of 

 it, and get into their possession the best-printed 

 labels we have yet seen, arranged in the order which 

 English botanists generally agree to be the best — 

 that of the London Catalogue. 



Eektilization of the Yucca Plant. — The 

 mode of fertilization of this plant has just been dis- 

 covered by Professor Riley, of St. Louis. It is per- 

 formed by a small white moth, called Brotiuha 

 Tuccasella, which forms the type of a new genus. 

 The female only has the basal joint of the maxillary 

 palpus wonderfully modified into a long, prehensile, 

 spined tentacle. With this tentacle she collects the 

 pollen, and thrusts it into the stigmatic tube, and 

 after having thus fertilized the flower she consigns 

 a few eggs to the young fruit, the seeds of which 

 her larvEe feed upon. The Yucca is the only insect- 

 loving plant known which absolutely depends for 

 fertilization on a single species of insect, and, as 

 has been shown, that insect seems modified for the 

 purpose. Tlie plant and its fructifier are inseparable 

 under natural conditions, aud the latter occurs 

 throughout the native home of the former. In the 

 more northern portions of the United States, and 

 in Europe, where our Yuccas have been introduced 

 and are cultivated for their showy blossoms, the 

 insect does not exist, and therefore the i^cc^s never 

 produce seed in those countries. The larva of the 

 insect eats through the Yucca capsule in which it 

 fed, enters the ground, and hybernates there in an 

 oval silken cocoon. In this stage the insect may 

 be sent to this country by mail, and our English 

 botanists may, by introducing it, be able to have 

 the Yucca produce seed after its kind. 



The Battle of Life among Plants. — A 

 capital article on this most important and interest- 

 ing subject appears in the last number of the 

 Popular Science Review, from the pen of Dr. 

 Masters. The examples selected are well-known 

 and common species of plants, such as Triticum 

 repens, Anacharis, &c. The article is a valuable 

 contribution to the theory of Natural Selection. 



Sequoia, anb its History.— This was the sub- 

 ject of an address delivered by Professor Asa Gray, 

 President of the American Association for the Ad- 

 vancement of Science, before the recent meetinp^. 

 It appears in full in the last number of the Annals 

 and Magazine of Natural History. The Professor 

 asks whether the Sequoias have played in former 

 times, and upon a larger scale, a more imposing part, 

 of which the present is but the epilogue ? We 

 cannot, he says, gaze high up the huge and venera- 

 ble trunks which people cross the continent to be- 

 hold, without wishing that these patriarchs of the 

 grove were able, like the long-lived ante-diluvians 

 of Scripture, . to hand down to us, through a few 

 generations, the traditions of centuries, and so tell 

 us somewhat of the history of their race. Pifteen 

 hundred annual layers have been counted, or satis- 

 factorily made out, upon one or two fallen trunks. 

 It is probable that, close to the heart of some of 

 the living ivees, may be found the circle that records 

 the year of our Saviour's nativity ! A few genera- 

 tions of such trees might carry the history a long 

 way back. But the ground they stand upon, and 

 the marks of very recent geological change and 

 vicissitude in the region around, testify that not 

 very many such generations can have flourished 

 there, at least in an unbroken sequence. When 

 the site was covered by glaciers, these Sequoias 

 must have occupied other stations, if, as there is 

 reason to believe, they then existed in the land. 



SpHiERAPHiDES OF SiLENE MARiTiMA. — A refer- 

 ence to the engravings in Science-Gossip, April J, 

 1870 (fig. 92, p. 99), will at once show the re- 

 markable difference between raphides and Sphae- 

 raphides. These last crystals abound in many 

 British plants, especially of the orders Caryophylla- 

 cefE, TJrticacese, Chenopodiaceae, &c., and may be 

 well examined in Silene maritima. In this plant 

 the Sphseraphides are so large as to measure about 

 Tal^ of an iuch in diameter, and so beautiful as to 

 afford most interesting objects, which may be very 

 easily preserved on a slide, to em-ich the cabinet of 

 microscopic phytotomy. — Q. F. 



Swans and Pish.— I should feel obliged if any 

 of your numerous scientific readers can inform me if 

 the swan destroys the spawn of fish, and if they 

 keep down the growth of weeds in rivers and lakes, 

 a question of great importance to those interested 

 in pisciculture. — F. G. P. 



