GNETOPSIS, SCHUTZIA, DICTYOTHALAMUS, CALATHIOPS. 129 



The tissue surrounding it was destroyed ; it could not therefore be deter- 

 mined with perfect certainty in which of the two parts its course lay. That 

 portion of the integument which encloses the apex of the nucellus behaves 

 in a very peculiar manner, and may be compared perhaps with Lagenostoma, 

 Will, (see above on p. 120). It attains a considerable thickness and separates 

 into a compact outer lamina (canopy ?) and a similar inner lamina, while the 

 cell-layer between the two is formed of extended filaments, which represent 

 so many cells and traverse a broad intercellular space at some distance from 

 each other. This looser tissue ceases of course at the micropylar canal, 

 where the outer and inner layer are in connection with one another. The 

 margin also of the orifice of the micropyle is formed of a cup-shaped ex- 

 pansion, which is seen to be drawn out at two points into long filiform ap- 

 pendages (Fig. n, A, B\ It is certainly possible, as Renault thinks, that 

 the loose open tissue surrounding the micropyle may have served as a 

 swimming-apparatus and the long filaments attached to it as organs of 

 flight, and that these seeds therefore were adapted at once for transport 

 through the air and through the water ; but we cannot grant more than 

 this. There seems to be much better foundation for his view, that the 

 drop of moisture excreted for the reception of the pollen-dust was caught 

 between the two long cilia, which served therefore as conducting organs 

 in the process of pollination. Organs of this kind must in fact have been 

 a necessity in the case of flowers buried among close-set woolly hairs and 

 overtopped by them. 



From the account here given it would certainly be impossible to guess 

 the reasons which have led Renault to place this genus among Gnetaceae. 

 But these reasons appear at once when we employ his terminology, and say 

 for example with Saporta and Marion l : ' the chief difference (between 

 Gnetopsis and Ephedra) is that the involucre or exterior pseudo-ovarian 

 integument encloses four ovules seated on a receptacular cushion, instead of 

 only one.' That is to say, that the leaves which were just now termed bracts 

 must be explained to be imperfectly closing carpels, and are to be com- 

 pared in accordance with van Tieghem's ideas with the outer covering 

 of the ovule of Ephedra and Gnetum. We may certainly incline to this 

 view from van Tieghem's stand-point, but even this does not compel us to 

 adopt it, as will appear on referring to the artificial interpretation of the 

 female flower of Taxus given by that author. It follows that if the assign- 

 ing our genus to Gnetaceae really rests on a petitio principii, we can only 

 properly say that it is a form of Gymnosperm, but that its affinities and 

 relations require further investigation. 



In conclusion, we must mention here a number of remains of fructifi- 



1 Saporta et Marion (2), p. 181. 

 K 



