278 



HARD WICKE ' S S CIE NCE- G O SSIP. 



each gradual development. Fig. B, 1, represents 

 a first difference from a stamen. This had one side 

 a unilocular anther, and the other side the portion of 

 a barren stigma ; that is to say, one which has no 

 viscid fluid to retain the pollen at the time of fer- 

 tilisation. If it had this fluid at that period, it would 

 be bi-sexual. The filament supporting this was the 

 same colour as the purple anther lobe ; the barren 

 stigma was of a shining raw sienna colour. Fig. 

 B, 2, represents the same a little more developed, 

 having a greater portion of the barren stigma, at the 

 former end of the filament was a little enlarged, and 

 of a bright green colour, resembling that of the 

 ovary ; this was about one-quarter of its whole 

 length; the other part was purple (Fig. B, 3), and 

 had one-quarter anther, and three-quarters barren 

 stigma, whose enlarged filament had one-half green, 

 of which the latter end was purple. Fig. B, 4, 

 had the filament capitulated with a barren stigma, 

 which was of a shining raw sienna colour ; the 

 filament was thick and hollow, and at the latter end 

 had a tint of purple. Fig. B, 5, had a thick hollow 

 green filament about one-eighth of an inch in 

 diameter; this supported a perfect but barren stigma. 

 Fig. b, 6, had the same filament, but thicker at its 

 upper end, having a larger stigma with a portion of 

 one of the canals on one. This canal contained the 

 viscid fluid for the preservation of the pollen. There 

 was a small barren syncarpous ovary ; this and the 

 preceding were coherent to the gyncecium (Fig. 

 B, 7), which represents a syncarpous ovary, with 

 two dissepiments. The stigma had two long perfect 

 canals, and on the opposite side were four lesser 

 abortive ones. The placentas had the neuclei (Fig. 

 B, 8), and there was a small syncarpous ovary with 

 parietal placentation, of which two had perfect dis- 

 sepiments, and four small abortive ones. This had 

 been fertilised with the gyncecium, and within it 

 contained matured seeds. Fig. d, is a longitudinal 

 section of the last mentioned, and would have been 

 a perfect syncarpous ovary bad it not been for the 

 abortion of one side ; and would have had six dis- 

 sepiments, with a six-lobed stigma, with six canals, 

 so that there would be a small syncarpous ovary, 

 with six dissepiments less than ordinary gyncecium of 

 this specie. 



Henry Ernest Griset. 

 Faygate, Sussex. 



NOTES ON STELLA RI A AQUATIC A, Scor. 



DURING the past summer some extremely viscid 

 specimens of Stellaria {Malaehium) aquatica, 

 Scop., have been growing on a small bed of river 

 gravel, thrown up by a serious flood in the River 

 Teme near here some years ago. These plants grow 

 close to the water's edge, and are without any pro- 

 tection from the sun's rays, which strike with much 

 force upon this small island. The stems are diffuse, 



decumbent, and very weak, their lower portions 

 being glabrous, while their upper portions are re- 

 markably viscid ; and this not only at the nodes, but 

 their internodes and very short petioles are also very 

 sticky, as well as the peduncles and calices. The 

 stems, where growing among other plants, trail over 

 them for some distance, and lengthen considerably ; 

 but others, obtaining no such support, lie close along 

 the ground, only becoming erect where they com- 

 mence to flower. It may be noted here that those 

 plants which grow in the open are very much smaller, 

 and are more than three times as viscid as those 

 growing among other vegetation. 



This stickiness has puzzled me much, and on 

 looking into the few authorities I have, I find but 

 little notice has been taken of it, or of the reasons 

 for viscidity generally, except as assisting cross- 

 fertilisation by preventing the access of small creeping 

 insects to flowers. Dr. Kerner (in "Flowers and 

 their Unbidden Guests," p. 52) says : " More re- 

 markable than all those caryophyllaceous plants in 

 which the peduncles are transformed into actual 

 lime-twigs." Dr. J. E. Taylor also says: "The 

 most widely adopted protective contrivance employed 

 by plants to protect their flowers is the secretion of 

 some sticky substance on the stems and calices ot 

 flowers, which act as a kind of 'lime,' in which the 

 greedy ants are sure to be caught and killed. The 

 order Caryophyllacere has been the most successful 

 in employing this device. . . . The reason for the 

 secretion of these sticky fluids by plants is a defensive 

 one" ("Sagacity and Morality of Plants," pp. 14 I, 

 142). Again: "Plant hairs in not a few instances 

 have been converted into glands, and now secrete 

 the viscous fluid which anoints the stems of flowers, 

 rendering them sticky and incapable of being 

 climbed" (Taylor's " Flowers : their Origin, Shapes, 

 &c," p. 316). 



These quotations (and others could be made) all 

 tend to one point — that the stems of viscid plants (of 

 which Stellaria aqjiatica is one) are glandular in 

 order to keep the flowers from being rifled of their 

 pollen and honey by creeping insects ; but is there 

 not another reason in this case ? The stems of 

 Stellaria aquatica are diffuse, decumbent, and very 

 weak, with the lower Dortion perfectly glabrous and 

 the remainder (two-thirds or more of their length) 

 extremely viscid. The explanation I venture to offer 

 is, that this viscid secretion, besides acting as a pro- 

 tection to the honey against the attacks of creeping 

 insects, is also a protection to the plant itself against 

 the extreme heat of the sun's rays upon its bare and 

 stony habitat. 



The objection which at once occurs is, naturally, 

 that it would be just as necessary for the lower part 

 of the stem as for the upper to be sticky. The 

 decumbent lower parts of the stems have, however, 

 only the heat from above to contend against, and 

 their diffuse stems covered by the lower leaves afford 



