OVULE. 43 



all. The Miseltoe and Santalum are examples of such 

 structure. 



234. In the cells of the tissue of which the coats of 

 the ovule are formed, often -p. 



exist large globules or 

 grains, as at (a) ; and 

 when the period of fertili- 

 zation approaches, a num- 

 ber of minute granules are 

 developed within these, 

 which latter seem to ex- 

 pand and lose their sub- 

 stance, whilst the minuter 

 granules alone remain, as at (&). 



235. The nucleus varies very much in form and ap- 

 pearance in relation to the other parts of the ovule, and 

 it sometimes protrudes at an early period of its forma- 

 tion beyond the foramen, as the endostome and exos- 

 tome, when spoken of collectively, are termed. The 

 only points at present concerning the nucleus to be con- 

 sidered, are those relating to its position or direction, 

 as under the function of generation the nucleus will be 

 referred to again. 



236. Between the coats of the ovule and the nucleus, 

 there is a connection kept up by means of the vascular 

 and cellular tissue, derived from the placenta in the 

 form of a.funiculus or cord. 



237. The funiculus consists of spiral vessels and cel- 

 lular tissue ; this bundle pierces the primine, its vascular 

 system spreading upon the secundine, whilst its cellular 

 connects the base of the 'nucleus with that coat. The 

 spot where this takes place is the true base of these 

 bodies, and the ramifications of the spiral vessels upon 

 the base of the secundine is termed the chalaza. 



238. When the base of the nucleus and secundine 

 (A a, fig. 44) is contiguous to the base of the primine (b), 

 and these are close to the true base of the whole ovule, 

 which is at the placenta (c), its axis being rectilinear, 

 we have an orthotropous ovule, as in the Nettle (A). 



