HARDWICKE'S SCIENCE-GOSSIP. 



George is of opinion that it may be a variety of 

 some other Family. Living specimens kindly supplied 

 by him, disclosed this crucial peculiarity, and substan- 

 tiate the division of the Group into those possessing 

 two eyes, the Hygrobatides, and those having four, the 

 Hydrachnides. 



In every exhibition ot Microscopic life, such 

 exclamations as " wonderful," " beautiful," " quaint," 

 are ordinary and natural forms of expression : so 

 perfect, startling, and novel, are such visions as re- 

 vealed by fine instruments, and, conceding this 

 sweeping admiration as a condition of the mental 

 excitement of a casual observer, most assuredly, to 

 the more experienced, rarely are seen gems of anima- 

 tion equal to these creatures when exhibited with 

 good illumination from an argand gas flame close to 

 the mirror, reflected through a carefully focussed 

 paraboloid. Under such conditions these dainty mites 

 (beyond eccentricity of form) disclose marvellous 

 beauty of colour,: scarlets, azure-blues, browns, greens 

 and yellows, of such delicate and subdued transfu- 

 sions, as might teach a lesson in tone to the finest 

 artist, and beyond this, a vivacity of motion, a 

 humour of attitude, that every swirl, every movement 

 reveals fresh shimmerings of light, and_more comical 

 postures. 



In the December, 1882, number of this Journal, 

 Air. George states that to convey even an ideal 

 representation of their beauty requires the assist- 

 ance of " colour." It may be added, as a matter of 

 experience, that even a mere semblance requires 

 something more ; the highest resources of the palette 

 can never approach " light," and what is the white 

 of drawing paper, or the most delicateresovrces of the 

 lithographer, compared with the glowing hues and 

 blazon of microscopical illumination ? 



The life- history of the Hydrachnea has been 

 fairly traced ; they are found in clear ponds, and 

 slowly running brooks,, easily discovered by their 

 peculiarity of motion and brilliancy ; a mustard seed 

 in dimensions, a ruby in appearance, routing about 

 with unmistakable carnivorous instincts ; in their 

 earliest stage they require hospitality ; at birth the 

 young swim freely, but eventually become com- 

 mensal, possibly parasitic on some aquatic insect. 

 They then assume a condition of passive content- 

 ment, increasing in size, and passing through suc- 

 cessive larval stages to a perfect condition, only 

 becoming free when ready for reproduction. This 

 is supported indirectly by Westwood, who, referring 

 to pond beetles, states, " notwithstanding their large 

 size, they are subject to the attacks of a minute 

 parasite,''' at that time considered to be a perfected 

 creature. But it was proved to be the immature state 

 of an Hydrachna, affixed as a minute oval bag with a 

 narrow neck to the upper side of. the abdomen, 

 infesting particularlyZ>_)'//.sr#.r margiualis, beneath the 

 elytra. It is possible the Hydrachnea might be 

 developed and reared in a tank in which the larger 



water beetles were kept and liberally fed ; it has been 

 observed that an excess of the larger life in a tank 

 will develop organisms not otherwise attainable. 

 Mexican axolotls, the size of young rats, fed once a 

 week on raw beef, have lived in captivity for several 

 years in a receptacle of very limited dimensions ; the 

 water never changed, but merely replenished, has 

 always been in all seasons a world of microscopic life. 



In their perfect condition, the Hydrachnea are 

 predatory, capturing with ease, and living upon 

 Entomostraca ; they may be preserved for months in 

 a vase with fragments of growing weeds ; but living 

 food must occasionally be supplied. They should be 

 examined "alive" under such conditions as will 

 subdue and restrict their activity. Mr. George states 

 that, if a specimen be isolated in a saucer in a drop 

 just sufficient to keep it endeavouring to swim, and 

 then deluged with hot water, it will exhibit all its 

 features, necessarily, in a passive condition. It may 

 then be transferred to, and closed in a cell, in the 

 same water, and kept sufficiently long to afford pro- 

 longed examination ; but, as permanent objects for the 

 cabinet they appear to be failures, the vascularity 

 rotundity, "tightness," and delicacy of their integu- 

 ments seem to defy any known preservative medium ; 

 " without pressure," they collapse, and become 

 wrinkled; flattened, " underpressure," their integrity 

 is too impaired, either for accurate observation, or 

 drawing. 



Crouch End. 



WINTER BOTANY. 

 CHILLON WOODS, MONTREUX. 

 (December 5, 1884.) 



WE had arrived at our Montreux quarters for 

 the winter, November 26th. After one or 

 two days of brilliant sunshine, a heavy snowstorm had 

 set in, fully six inches lying on the ground for the 

 next thirty-six hours. This was followed by a rapid 

 thaw with several very bright sunny mornings. On 

 the morning of December 5th, we determined to re- 

 visit some of our old haunts, choosing a well-known 

 path leading from Territet through the upper village 

 of Vey taux, and climbing the wooded mountain slopes 

 to descend on the opposite side by the] woods and 

 Chillon Castle. In previous years we had found an 

 endless wealth of mosses, lichen and fungi, with some 

 few interesting flowers still lingering as late as 

 December. Nor were we disappointed in our 

 search. Even in the snow-covered patches the hardy 

 little Gentiana verna had opened its wonderfully blue 

 corolla under the influence of the genial sun, and we 

 counted twenty-four separate plants, at an elevation 

 of 1500 feet above the sea in full vigorous bloom ; 

 they were smaller plants, it is true, than the ordinary 

 spring growth, but equally brilliant in colour. Hard 



