MEDULLOSEAE 



459 



Renault, however, actually anticipated the discovery of 

 Ikeno and Hirase. In an allied seed, Aetheotesta, as 

 well as in Steplianospermum itself, the cell-walls of the 

 pollen -grains which they contain are perforated, and 

 Renault suggested, in 1887, "that the perforations 

 served for the passage of mobile bodies analogous to 

 antherozoids." He adds : " We do not regard as 



Fig. 174. — Slephmwspermmn a-kenioidcs. Multicellular pollen-grains in pollen-chamber ; 

 some shreds of the wall extend into the cavity. The middle pollen-grain is in 

 transverse section, and shows the radiating septa dividing up the grain. The grain 

 to the right is in longitudinal section, and shows the peripheral cells and the 

 "replum" in the middle (see text), x 137. Univ. College Coll. S 7A. From a 

 photograph lent by Prof. Oliver. 



impossible the existence in the past of pollen-grains, 

 which, instead of effecting fertilisation by means of a 

 tube, discharged into the pollen-chamber of the appro- 

 priate seeds antherozoids capable of performing this 

 function." l 



1 Renault, " Note sur le Genre Aetheotesta," Me'm. deSoc. d Hist. Nat. de 

 Saone-et-Loire, pp. 156, 158, 1887. For Stephatwspermiwi see Brongniart, 

 Graines Fossilcs Silicifie'es, 188 1 ; Renault, Coins de dot. fossile, t. iv. 

 p. 184, Plates xxi. and xxii. 1885 ; F. W. Oliver, " Structure and Affinities of 

 Stephanospei-mnm," Trans. Linn. Soc. London, 2ndser. Hot. vol. vi. Part 

 viii. 1904. 



