﻿z 4 SCOTT, Early History of Seed bearing Plants. 



Trigonocarpon olivaeforme, so frequently associated with 

 Medullosa anglica or its Alethopteroid foliage, agreed 

 with the vegetative organs of that plant in certain 

 structural details. I feel little doubt myself that this 

 attribution is correct, though more decisive evidence is 

 needed. The genus Trigonocarpon includes some of the 

 most familiar seeds of the English Coal-Measures, frequent 

 tooth as casts and as petrified specimens. Most of the 

 casts are merely internal moulds of the seed-cavity, as 

 Williamson pointed out, but more perfect specimens, show- 

 ing the testa and the form of the seed as a whole are also 

 met with. The testa, as shown in the petrifactions, had 

 a complex structure, the thick, hard, and ribbed inner 

 layer being enveloped in a fleshy outer envelope. It 

 -was the agreement in structure between the external 

 membrane of the fleshy envelope and the corresponding 

 layers of the petiole in Medullosa anglica, which led 

 Mr. George Wild to suspect that the seed and leaf might 

 belong to the same plant (Wild, 'oo). A remarkable 

 feature in the seed Trigonocarpon is the great prolongation 

 of the winged micropylar tube, which considerably exceeds 

 the body of the seed in length (PI. III., Fig. 4). 



Although it is only in the case of Nenropteris Jietero- 

 phylla among the Neuropteridese that we have as yet 

 direct and conclusive proof that seeds were produced, it is 

 obvious that this cannot have been an isolated instance. 

 If we further take into account the indications just men- 

 tioned in the case of Alethoptei'is and Trigonocarpon, the 

 anatomical evidence demonstrating a clear relation of 

 certain members of the family to Cycadophyta, and the 

 constant absence of any sign of a cryptogamic fructifica- 

 tion, it can scarcely be doubted that the whole of the 

 Neuropterideae, in so far as they constitute a natural group, 

 were seed-bearing plants. 



