298 ON SEEDLINGS 



the base, partly surrounding the radicle, and minutely emar- 

 ginate, apparently owing to the indentation of the testa at the 

 thickened chalaza. In I. chinensis there is sometimes a slight 

 depression at the chalaza, which occasionally is quite marked. 

 The seeds of I. Roylei are pyriform with a small depression at 

 the broad apical end, and rough with small points. The 

 embryo is similar to that of I. parviflora, and the cotyledons 

 are broadly obovate with the apical notch well marked. 



5. The fifth group, in which endosperm is absent, and 

 the cotyledons convolute or induplicate-plicate, is represented 

 by Geranium, Erodium, Monsonia, and Sarcocaulon, of the 

 tribe Geranieae, and Pelargonium of the Pelargonieae. The 

 various species of Geranium have the most complicated embryo 

 of the three better known genera, and constitute the best typfe 

 of the group. The ovary consists of five carpels, is deeply 

 five-lobed, five-celled, and ten-ovuled. The axis is greatly pro- 

 longed between the carpels, and each of the latter is produced 

 into a long beak attached to the axis, except near the top 

 where they separate into five branches, which are stigmatose 

 along their inner face. The geminate ovules are slightly 

 superposed, incurved, and semianatropous. The hilum is 

 ventral, and above the middle of the seed, and the micropyle 

 is on the upper side of this. One of the two ovules only 

 becomes fertilised, and in a number of specimens examined it 

 has always been the upper one. The seed is oblong or sub- 

 cylindrical, finely tuberculated, about equally thick at both 

 ends, and fixed to the placenta a little above its middle. The 

 chalaza is at the lower end close to the base of the carpel. 

 Endosperm is absent, and the curved embryo, which is green, 

 at least while fresh, occupies the whole of the seed. 



Taking G. Wallichianum as a type, we find that the 

 radicle is the only part that is curved ; and assuming that 

 the embryo starts from near the micropyle above the middle 

 of the seed, then it would grow until it reached the upper 

 end, when the apex curves downwards until it reaches the 

 base, and here we always find the apex of the cotyledons 

 pointing to the base of the carpels or ovary. There still 

 being room for the cotyledons to develop laterally, they com- 

 mence to coil longitudinally round the sides of the seed in the 



