i9°9l 



THOMSON— SAXEGOTHAEA AND MICROCACHRYS 349 



In Microcachrys a single vascular bundle supplies leaf and sporo- 

 v\\. There are no resin canals in the stem nor in the axis of either 



phyll. 

 cone, 

 beneath the 



It is not until well out into the sporophyll that a canal is found 



fig. i j) . The canal of 



oeneatn me vascuicu uuuuic ^iit & aj t /ww r . v .., ro . -^, 



the vegetative leaf, however, is continued downward into its swollen 

 base, and the leaves being concrescent, there is the appearance of 

 resin ducts in the stem. The vascular bundle in both leaf and 

 sporophyll runs closer to the upper than the lower surface. A com- 

 parison of longitudinal sections of the megasporophyll and vegetative 

 , , . ,, i . 4 u„ j,v+oi nort nf the former 



■emblance 



and the whole of the latter. There is a distinct palisade on the lower 

 surface of each, a sclerotic hypoderma, and an epidermis with a very 

 thick cuticle and no stomata, the latter being restricted to the upper 

 surface, and in the case of the sporophyll, so far as I have observed, 

 to the region beyond the ovule. There is no hypoderma on the upper 

 surface, and the same kind of degenerate-looking palisade tissue 

 occurs in both sporophyll and leaf. Proximally the sporophyll is 

 contracted into a slender stalk, while the leaf is concrescent with tne 

 stem. The vascular supply of the ovule originates in much the same 



"^j aa in OctACgUlllcLCci Willi at inov **v ~ rr - 



the resin canal come bast and wood of the main bundle and above i 

 center of the latter the few wood elements of the ovular supply . 

 On separation the ovular supply bundle passes obliquely upwar 

 as in Saxegothaea (cf. figs, n and 13), with bast clearly evident on 

 its upper side. In Microcachrys, the single supply bundle bifurcate 

 near the base of the ovule, the divisions passing well into 



part of the integument. 



few nucle 



how 



my 



• • 



In one case. 



in a parietal stratum 01 pn^p— ~ w o • < he(TOnia l 



— , a oroth.llial tissue (fig. ifi » P resent ** ^Zn^irom 

 initials discernible. These are located at considerable distance ^ 

 oneanother. Around the prothallium the mega spore-coat is 

 ^hle type. It is slightly thicker than in ^""g^Z 

 *ge. Lik e the pine coat at this young stage, it * of ^ 



6 Cf. Worsdell, Observations on the vascular system of the 



Comferae. Annals of Botany 1 3 : 538- i«99- 2vmn osperms. Univ. of 



7 Thomson, R. B., The megaspore-membrane ot tn w 

 Pronto Studies, Biol. Ser. 4: 1-64- &■ *S- I 9°5- 



