822 RECORD OF CURRENT RESEARCHES RELATING TO 



cells are produced regularly, with originally equal power of develop- 

 ment, until one of them, usually the central one, attains the upper 

 hand, so that finally only a single embryo-sac is produced. 



In Chenopodium and Sabulina only primary daughter-cells proceed 

 from the mother-cell. By division of the lower of these a row of 

 tlireo cells is produced in AUionia, Goinphrena, Cydonia, Geum, and 

 Mi/osurus, exceptionally in Chenopodium. Four secondary daughter- 

 colls api^ear in Delphinium, Itibes, Helianthermim (in this case as 

 many as six), Sanguisorha, Huhus, Polygonum, and Hippuris. In 

 dialypctalte it is always the lowest cell of the row of daughter-cells, 

 whatever their number, and this only, which develops into the 

 embryo-sac ; the only exception at present known occurring in B,osa 

 livida. 



Fertilization of Cohsea penduliflora.* — Mr. A. Ernst, writing 

 from Caracas, describes his observations showing the peculiar circum- 

 stances under which the flowers of this plant are fertilized. 



The flowers have little to attract attention,, being dull green in 

 colour, with very little red on the filaments, and no smell. The 

 plant climbs in the same manner as C. scundens, described in Darwin's 

 ' Climbing Plants.' The flowers grow on long peduncles, which gene- 

 rally have a horizontal position, projecting some five or six inches from 

 the mass of the foliage. When the calyx opens, the filaments as well as 

 the style are irregularly twisted ; but in about two or three days all 

 become straight. The style hangs obliquely downwards ; the fila- 

 ments all bend sideways, the bend being inside the tube of the 

 corolla, a little over the hairs at their base. There is often a distance 

 of 15 cm. between the anthers of either side. About 5 or 6 p.m. 

 the anthers burst, and soon after the style rises and assumes 

 a central position, so that there is a distance of about 10 cm. 

 between the stigmas and any of the anthers. Only then is nectar 

 being secreted (very copiously) by the glandular disk round the base 

 of the ovary, and it appears therefore when the anthers have done 

 their work ; even an hour before their rupture no trace of it is to be 

 found. The nectar-cavity in the tube of the corolla is completely 

 shut up by the numerous spreading hairs at the base of the filaments, 

 so that an overflow is impossible. The grains of pollen are very 

 large (0 • 2 mm. in diameter) and of the same structure as in Cobcea 

 scandens 



Several weeks passed at first before the manner of fertilization 

 was witnessed. The stigmas were every morning carefully examined, 

 but no pollen could be discovered on them. The filaments twisted 

 back again and got somewhat frizzled, after one single night's 

 expansion. About noon the corolla drops off, separating from close to 

 the glandular ring, and then slipping down over the style, which, by 

 this time, is again in a relaxed hanging position. There is always 

 some nectar in the tube of the corolla after its separation, but none 

 remains in the calyx round the ovary, nor does its secretion 

 continue. 



* ' Nature,' xxii. (1880) p. 148. 



