RECEPTACLB. 457 



A shortened condition of the flower-stalks occurs 

 occasionally, greatly altering the general character of 

 the inflorescence. This has been observed in pelar- 

 goniums and in the Chinese primrose, in both of which 

 the effect was to replace the umbellate form of inflor- 

 escence by a capitate one. 



Abortion of the receptacle. Here may be mentioned 

 those cases of flowers with habitually inferior ovary 

 (real or apparent), in which the receptacle fails, from 

 some cause or other, to dilate as usual. This has 

 already been alluded to under the head of Prolification, 

 Displacements, &c. (pp. 78, 130, &c., figs. 85 37, 64, 

 &c.), and hence requires only incidental comment in 

 this place. There are, however, certain other cases 

 of a similar nature which may here be referred to; 

 such as the abortive condition of the inferior ovary, 

 or rather of the receptacle, that usually encircles the 

 ovary in Compositce and TJmbelliferce. In the former 

 natural order the following plants have been met 

 with in this condition : * Tragopogon pratense !, 

 *Cirsium arvense, Hypochceris radicata, Senecio vulgaris !, 

 Coreopsis Drummondi. In the latter order, Daucus 

 Carota! (Enanthe crocata! and Thysselinum palustre, 

 seem most frequently to have been observed in this 

 state. ^ In some gourds the receptacle may be seen 



the following account of the formation of this peculiar growth : " In 

 the autumn the parent aphis deposits her eggs at the base of the 

 embryo leaves, within the bud destined to produce the shoots of the 

 following year. When these begin to burst and expand in spring, the 

 leaves, at whose bases the eggs have been deposited, instead of increas- 

 ing in length, enlarge at the base, and form a cell or cyst whose mouth 

 is at first closed by a red velvety-looking substance. If opened in this 

 state a nest of small greenish aphides is distinctly visible, and at a 

 certain period, or when they have acquired maturity, which is towards 

 the end of the summer, the mouth of the cell opens and the insects fly 

 off to inflict a similar injury upon the nascent buds of the year. In 

 some instances the leaves of only a portion of the circumference of a 

 shoot are affected, in which case, though a sUght distortion may take 

 place, the branch is not prevented from elongating; but in others, 

 where the whole of the leaves around the shoot are converted into 

 nidi, elongation is prevented and distortion to a great extent takes 

 place." 



' See Cramer, ' Bildungsabweich.,* pp. 53, 64, for further references. 



