6 1 



HARD WICKE' S SCIENCE-GOSSIP. 



their pollen, and to make assurance doubly sure for 

 some time keeps its four-lobed stigma closely shut. 

 Last but not least, we arrive at the sweetest flower 

 of the garden — Mignonette. The drawing (Fig. 36) 

 does not profess to be complete, but is accurate as 

 far as it goes. The fringed petals have been removed, 

 as well as some of the stamens, in order to give 

 prominence to the nectary, which is formed by the 

 peculiarly-shaped disk of the ovary. The flower is 

 proterogynous, and during its first stage the red 

 anthers hang down below the pistil with its horned 

 stigmas, but gradually rise up as they dehisce into 

 such a position that no insect can approach the 

 nectary without passing over them and getting dusted 

 with the pollen. 



The study of even a small number of flowers with 

 reference to the position of their nectaries shows that 

 those most admired for their elegant shapes or lovely 

 colours, or that delight us with their delicious scents, 

 seem to be just those that conceal their honey from 

 the multitude and invite to their banquet only the 

 favoured few. It is bees, as many botanists believe, 

 who, by their special diligence, have helped to 

 modify to an almost inconceivable extent the forms 

 of flowers, though none the less, we may be assured, 

 under the guidance of an unseen Hand. There are 

 both advantages! and disadvantages in the conceal- 

 ment of honey, the advantages being chiefly those of 

 protection from rain and the possibility of accumulat- 

 ing it in greater quantity in spurs or tubes, and thus 

 increasing its attraction to those visitors for whom it 

 is intended, and excluding the short-lipped insects 

 whose visits are unwelcome. The disadvantages are 

 that it is not so easily found by welcome guests and 

 that a host of possible friends is excluded. Still 

 on the whole the advantages are greater than the 

 disadvantages, because a greater number of the most 

 intelligent are attracted, and their way to the deeply- 

 placed honey is made easy to them by the so-called 

 honey-guides, whether these be specially con- 

 spicuous markings on the corolla, or grooves or 

 passages made by its folds, or hairs that obstruct the 

 way, except in the desired direction, or other equally 

 effective arrangements ; but the subject is a wide one 

 and can only be hinted at here. Some botanists 

 consider honey to be a waste product of the plant 

 and to stand in the same category as wax, gum, resin, 

 etc., so that according to this view it must be 

 supposed that no special expenditure of energy goes 

 to its production ; on the other hand it seems highly 

 improbable that a substance secreted in so many 

 instances by a special set of cells and guarded from 

 injury or plunder with so much care, should be a 

 waste product. Be this as it may, there is usually 

 plenty of it in the nectary cells, and often the 

 irritation induced by an examination of the flower 

 will cause it to flow out in still greater abundance, 

 which shows that the secretion may be less or greater 

 according to the demands made upon it. 



POND LIFE STUDIES. 



No. IV. — Something about a Green Water- 

 Dragon (Hydra viridis). 



By H. Durrant. 



WHEN Trembley made known his wonderful 

 discoveries ; on the freshwater Hydra, no 

 small stir was created. The most learned of savants T 

 belonging to the most learned of societies, became 

 so engrossed that nearly everything else was for- 

 gotten in the prosecution of their countless and 

 interesting experiments on this little animal. Courts 

 commissioned their ambassadors to supply them with 

 the latest news concerning such an all-engrossing, 

 theme, and scientists with brotherly solicitude for 

 those amongst them who had not yet had a chance 

 of investigating, forwarded living specimens to them 

 as carefully as may be. The thing I was so unpre- 

 cedented, so contrary to every erst-while notion 

 of animal-life that it was only to be expected that 

 there would be numbers who would set their backs 

 against Trembley's announcements, and ridicule them 

 as idle fancies, products of the dead season, and akin 

 to the more modern green moon or great sea-serpent. 

 Not that the animal had just burst across the 

 scientific horizon in the full splendour of freshness. 

 It was 1744 now, but as far back as 1703 Leeuwen- 

 hoek had discovered it, and about the same time 

 a correspondent of the Royal Society reported the 

 same discovery in England. So that it was not 

 particularly 'new, and, as an animal apparently with 

 nothing of extraordinary interest about it to recom- 

 mend it, had ceased from calling forth much attention, 

 until Trembley, the immortal Trembley, stepped on 

 the field, and all Europe stood spell-bound by his 

 revelations. 



All this happened a century and a half ago. Now 

 the Hydra is among the commonest of the animals 

 that usually figure in the microscopist's dissecting- 

 trough. It has almost ceased to become a wonder, 

 but this is perhaps bred of familiarity. However, 

 there are still many, even now, who have never 

 heard of Trembley. Can it be wonderedSat, then, 

 that they should never have heard of the Hydra, at 

 least the name to them is shorn of any familiar fact 

 or picture, some fabulous monster perhaps. To 

 these, then, I would say, read patiently on, and stern 

 facts, if not elegant diction, shall stir you (though 

 less powerfully, perhaps), as they did in that memor- 

 able year of grace, 1744- 



If you go down to some tarn or slow-running 

 brook, and push aside the duckweed which covers 

 the surface like a thick green carpet, you will 

 probably see attached to the submerged leaves and 

 stems, little balls (scarcely the size of a small pea) 

 of a green jelly-like substance ; probably you may 

 not. In either case you had better bring home a. 

 small quantity of the plant in a rubber-bag or some- 



