202 



GYMNOSPKRMS 



A striking feature of the ovule is the collar. It is conspicuous 

 throughout the development of the ovule, but is proportionately 

 larger during the earlier stages (fig. 215). Fujii found many ovules 



Fig. 217. — Ginkgo hiloha: abnormal development of ovulate structures; Oj bud; b, 

 nearly normal strobilus; c, leaf with irregular thickenings; dj leaves bearing ovules; c, 

 ovule;/, thickening at base of ovule; g, longitudinal striation along fleshy part of seed. — 

 After Fujii, "9 



borne on more or less modified foliage leaves (fig. 217). These ex- 

 ceptional cases led to the conclusion that the collar is a modified leaf- 

 sporophyll bearing an ovule. The fact that the peduncle has four 

 vascular bundles, while the petiole of a leaf has only two, strongly 



