322 GENERAL REVIEW. 



assume that to have been one of the parents crossed with one 

 of the pink-flowered Zonals of the Christine type. 



P. oblongatum (see ' Bot. Mag.,' t. 5996), a recently-intro- 

 duced species, with thick fleshy stems, and clusters of yellow 

 crimson-streaked flowers, has attracted the attention of hybrid- 

 isers, who have attempted to infuse its yellow colour into the 

 Zonal and fancy races. The method most likely to prove 

 successful would be to originate a new race of tuberous-stemmed 

 varieties, by crossing it with other allied species of similar 

 habit. 



Pelargonium tetragonium is a curiosity, having square stalks 

 or stems, and small -lobed leaves, which in one variety are 

 margined with bright rose. The flowers are large, the lower 

 petals being much reduced (see ' Bot. Mag.,' t. 136). 



Mr E. J. Lowe of Highfield, Nottingham, has for several 

 years endeavoured to obtain seedlings between Pelargonium 

 " Madame Vaucher," and Geranium sanguineum, and believes 

 he has effected this bigeneric cross.* Some of the seedlings have 

 flowered, the colours being white, rose, and red, and in some 

 of these supposed hybrids the leaves are curiously contorted, 

 but it is difficult to believe that they are really hybrids between 

 the two plants named. Mr P. Grieve fertilised an ivy-leaved 

 Pelargonium, the day after it had been fecundated with its own 

 pollen, with pollen of a variegated zonal 'variety, and the seed- 

 lings, which have not as yet flowered, are extremely variable ; 

 so variable, indeed, as to lead one to infer that the cross had 

 been influenced by the application of foreign pollen to the 

 flower after fertilisation with its own. Dr Denny's experience 

 is that the pollen-bearing parent is prepotent, and this is borne 

 out by his numerous experiments. His mode of manipulation 

 is thus explained by himself : " When I have ascertained by 

 means of my lens that the stigma is in a virgin and suitable 

 condition for impregnation, I immediately smother it with the 

 pollen I purposed employing ; and it is owing to this smother- 

 ing of the stigma by the pollen, as I am informed by Professor 

 Duncan, that I derive the prepotent influence of the male 

 parent ; because he says he has found, by careful experiments, 

 that if the ovule be impregnated by the application of a single 

 grain of pollen to the stigma, it is nourished principally by the 

 mother plant, which the offspring will in that case most re- 

 semble; but if a large quantity of pollen be applied to the 



* Mr Grieve attempted to obtain hybrids from Geranium pratcnse by 

 using pollen of silver- variegated zonals, and some of the seedlings appeared 

 with variegated foliage (see ''Gardeners' Chronicle,' 1876, Part L, p. 699, 

 and Part II., p. 49). 



