﻿8 SCOTT, Early History of Seed-bearing Plants. 



L. ovoides, and L. physoides, especially the latter. The 

 great number of pollen-grains occurring within the pollen- 

 chamber of both recent and fossil plants possessing this 

 mechanism, suggested to Sir Joseph Hooker the question 

 whether insects, possibly attracted by a secretion from the 

 glands in the case of Lagenostoma, might not aid in the 

 fertilization, a point which has not yet been determined. 



Text-Fig. 3. Lagenostoma Lomaxi, the seed of Lygino- 

 dendron. Apex of seed, in median longitudinal section, showing 

 the upper part of testa, enclosing the pollen-chamber at the top 

 of the nucellus. ot, outer layer of testa ; r, palisade-cells ; i.t. t 

 inner layer of testa ; s,s, cavity between testa and nucellus ; <?, 

 orifice of pollen-chamber ; pc, the actual pollen-chamber, lying 

 between its outer wall and the central column, cc. ; pg, pg, 

 pollen-grains lying in pollen-chamber ; pi, upper part of nucellus ; 

 mg, part of membrane of megaspore or embryo-sac ; after 

 Oliver ; x about 70. 



The pollen-grains found in the seeds have a character- 

 istic, apparently multicellular structure, which, apart from 

 its evident morphological interest, may prove of 

 importance in enabling us to identify the corresponding 

 male fructifications, not known with certainty as yet, 

 either in the case of Lyginodendron or in that of any 

 of the fern-like seed-plants of the carboniferous. Miss 



