CORDAITEAE. 113 



stalk, is perfectly naked, and consists of a few linear elongated cylin- 

 drical sessile erect pollen-sacs, which are attached by their base and form 

 a tuft by their divergence. Judging by the figures of the transverse section, 

 (Fig. 8, A) the pollen-sacs are usually five or six in number. Their walls 

 are formed of a palisade-like cell-layer, and open by a longitudinal fissure 

 placed on the side towards the tuft and extending down the whole length 

 of the sac. What is here spoken of as the flower is termed by Renault the 

 stamen ; this author speaks of the flower as follows : ' These flowers are 

 extremely simple, being formed of a few stamens only, which are either 

 scattered about in groups of two or three, or appear singly in the middle of 

 the sterile bracts.' It is just the latter circumstance, namely that the flowers 

 in the axils of the leaves are always reduced to a stamen of this kind, which 

 leads me to regard each of these organs as a simple flower, and the part 

 that bears it as a flower-stalk, not as a filament. That they are grouped 

 together at the summit admits also of an easy explanation ; the growth of 

 the bracts may have been arrested at this spot. And all the flowers, if 

 understood in this way, are alike in character, whereas according to 

 Renault's view their mode of development is different in different parts 

 of the inflorescence. Lastly, the view here taken is supported by the cir- 

 cumstance, that all the organs which are collected together at the apex 

 of the shoot, while differing from one another in length and age, are 

 arranged according to the requirements of acropetal order of de- 

 velopment l . 



The pollen-grains (Fig. 8, C) are found in the loculaments, and-occur 

 also scattered about in great abundance in the siliceous fragments. They 

 are ovately elliptical, their dimensions according to Renault being 0-9 and 

 0-5 of a millimetre. They are as a rule well preserved, evidently owing 

 to the cuticularisation of their outer membrane, and their surface is orna- 

 mented with a fine shagreen-like reticulation. Within and adjoining the 

 cell-wall on one side is the cell-group characteristic of Gymnosperms, 

 which shows a remarkably high degree of development, and consists of an 

 unusual number of thick-walled irregularly polygonal cells united together 

 into a tissue. 



Quite similar conditions are observed also in the two other species 

 described by Renault, in which however the flowers are all crowded to- 

 gether at the summit of the shoot, there being none that are axillary and 

 peripheral. Cordaianthus Saportanus moreover has a very short flower- 

 stalk 2 , and in C. subglomeratus the buds of the inflorescence are crowded 

 together in clusters 3 . The figures also given by Grand' Eury may belong 

 to this or to a similar species 4 . 



1 Renault (1), t. 16, f. 13. 3 Renault (]), t. 17, f. 3. 3 Renault (1), t. 17, ff. i ; 2. 



Grand' Eury (1), t. 26, f. i. 



