70 



Prof. W. C. Williamson on the 



[May 18, 



which the Tascular cylinder assumes the exogenous Diploxyloid organi- 

 zation. All the plants of which steins and branches have been found 

 displacing an organization corresponding to that of hring GrjTnnosperms 

 are still comprehended T^ithin Endlicher's genus Badoxijlon, On the 

 other hand, recognizing in Trigonocar-^um all the external features of a true 

 seed, the author cannot admit the probability of its having belonged to 

 the Lycopodiaceous Sigillarice. 



Gymnospermous Seeds. — Attention is next directed to the curious seeds 

 discovered in America, and published in Professor JN'ewberry's 'G-eological 

 Survey of Ohio.' These, however, merely display external forms. Still 

 more remarkable is the collection of such seeds found by IsL Orand-Eury 

 at St. Etienne in France. These exhibit their internal structure in a 

 wonderful manner, as is shown by M. Brongniart's brief memoir pub- 

 lished in the ' Annales des Sciences Xaturelles.' M. Brongniart called 

 attention, in that memoir, to a remarkable organization of the micropylar 

 extremity of many of these seeds, where a peculiar cavity existed, between 

 the micropyle and the apex of the nucleus, into which the pollen-grains 

 obtained entrance through the micropyle, and were thus brought into 

 contact T^ith the nucleus. In a more recent memoir on the fertihza- 

 tion of the ovules of some species of recent Cycads {Ceratozcvmice), 

 M. Brongniart sho-u'ed that a mammillar prolongation of the apex of the 

 nucleus projected into the micropyle, which it filled ; but that during 

 fertilization the cells of this prolongation became disorganized, and a 

 cavity was produced into which the poUen-grains found their way, the 

 apex of the nucleus below this cavity becoming covered over by true peri- 

 spermic membrane. These structural peculiarities so far accord \cith what 

 he observed in 31. G-rand-Eury's seeds, as to lead him to surmise that the 

 latter had Cycadean rather than Coniferous affinities. 



The author has found a number of remarkable seeds of a similar type 

 to those from St. Etienne in the Oldham nodules, and he has been in- 

 debted to his friends 3Ir. Butterworth and 3Ir. Xield, of Oldham, and 

 to Captain Aitken, of Bacup, for a few others. 



The first of these is a very small, nearly spherical seed, which the 

 author names Lagenostoma ovoides, about '16 of an inch in length 

 and '1 in breadth. It has a solid testa, within which can be recognized 

 two distinct membranes — an inner or " perispermic " one, which has 

 enclosed the endosperm, and an outer or " nuciilar one, which has been in 

 close contact with the perispermic one throughout the greater part of 

 the seed, but which splits up at its apex into two portions, the inner one 

 of which forms a remarkable flask-shaped canity, which the author de- 

 signates the lagenostome. Its base has rested upon the apex of the peri- 

 sperm, and its upper extremity has been continuous with the micropyle. 

 Within this lagenostome is a little dehcate parenchyma, which has shrimk 

 up towards the centre of the cavity, leaving a surrounding space in 

 which, in some examples, the author has found the objects regarded by 



