TRAQUAIRIA, SPOROCARPON. 185 



side while it was rotting in the water, especially as other sporangia of the 

 same cone contain small remains of tissue, which could not have got there 

 in any other way. And if the Traquairiae and Sporocarpae are macrospores, 

 how shall we explain the cells inside them ? Evidently there is nothing left 

 but to consider them to be remains of the pro thallium 1 , the preservation of 

 which, considering its delicate nature, would not be too probable. Now 

 these interior cells will give us less trouble, if with Strassburg and myself 

 we compare the entire bodies with the massulae of Azolla. In this case 

 they may be either spores, or else remains of single vacuole-spaces of the 

 spongy net-work of massulae which surrounds the spores. The one and 

 the other may perhaps be there together. I have for instance seen in some 

 preparations in the collection of Mr. W. Cash two different kinds of interior 

 cells, both sharply defined, but in the one case with a single circumscribing 

 line, in the other with an evident doubly-contoured membrane. Williamson 

 objects to our view, that there are indubitable macrospores with interior 

 cells, which are recognisable by their shape and by their strongly thickened 

 membrane beset with appendages on the outside. It is certain that there 

 are receptacles of the kind which come very near in form to undoubted 

 macrospores, as will be seen by comparing the figures which Williamson 2 

 has given of both these objects. But that the outer surface of the massulae 

 could vary much in character is shown by the differences which we find in 

 this respect in the few living representatives of the genus Azolla ; and the 

 perinium of the macrospores which has a similar origin may easily have 

 developed a similar configuration to that of the other sexual form. In 

 conclusion, I may say that nothing has confirmed me in this view of mine 

 so much as a preparation quite recently made by Mr. Binns and not yet 

 described, which I had the opportunity of seeing when I was with Mr. Cash. 

 A dark very thick-walled capsule resembling a macrospore encloses a num- 

 ber of cell-like spherical bodies closely crowded together, each of which is 

 filled quite full with small well-preserved microspores. In the same pre- 

 paration is another similar capsule containing only a single mass with a 

 frothy vacuolated appearance. The obvious view is that the capsule is 

 a sporocarp, in which the solid tissue is no longer visible, and that the 

 globular bodies are massulae which conceal spores. The other specimen 

 would in that case answer to an imperfectly developed conceptaculum, the 

 contents of which had stiffened into a sporeless ball of froth. However, I 

 have no doubt that by continued research we shall in time arrive at a more 

 perfect understanding of these objects. 



Williamson (1), ix, p. 345. - Williamson (1), ix, t. 23, ff. 64, 66. 



