298 CONIFERS. [chap. 



the number of possible embryos. Each cell resulting from 

 this division then repeatedly divides transversely, and at the 

 same time grows down into the substance of the endosperm, 

 which increases rapidly in bulk and finally displaces the 

 entire nucleus of the ovule. Of all the nascent embryos 

 contained in the same fertilised ovule but one attains 

 maturity, the rest being arrested at an early stage. As 

 the endosperm is not all absorbed during maturation, the 

 seed is albuminous. 



Besides the peculiarity in the structure of the flower of 

 Coniferae, the Order is characterised by the absence of 

 vessels in the wood, which consists of tapering wood-cells, 



Fig. 191. Female inflorescence of Fig. 192. Seed of same, bearing a 



Juniper. few resin-receptacles. 



marked on the sides, towards the medullary rays, with 

 circular disks, which answer to the margins of minute, 

 lenticular, intercellular cavities occurring between the " pits " 

 of adjacent cells. In the Pines and allied species, the 

 cotyledons are usually numerous, varying from three to 

 eighteen ; hence the term polycotyledo7ious applied to them. 

 As in other respects the structure of the Coniferai approaches 

 that of Dicotyledons, they are usually classed along with 

 them as an anomalous Family. 



