26 



FOSSIL PLANTS. 



Most of the sporangia in this cone are disarranged, or their sections are such as not 

 to give us a good idea of their original form ; but they are all full of sporehke bodies. 



Pig. 2 (No. S) is a cone rather less than one third of an inch in length, magnified 

 fourteen diameters. It gives evidence of eight receptacles (all holding sporangia, more 

 or less disarranged and containing a few spores), eight sets of scales or leaves, and spo- 

 rangium-bearers, both in tangential and longitudinal sections, as follow : — in each 

 of the first four receptacles, going downwards from the top, are two tangential sections : 

 in the 5th, two longitudinal sections and one tangential : in the Cth, one longitudinal 

 and one tangential section: in the 7th are two longitudinal sections, showing portions of 

 the sporangium-bearers, connected with the central axis of the cone : in the Sth, there 

 are no remains of the sporangium-bearers ; but a portion of the base of a scale and the 

 whole of the terminal part of that organ are visible. 



In this figure, although the section only shows a portion of the column, the form of 

 the scales and leaves forming the receptacles is well shown in the lower part. This 

 specimen in all respects so exactly resembles that of fig. 1, that it requires no further 

 description. 



Pig. 3 (No. 9), magnified nineteen diameters, is a tangential section of a single recep- 

 tacle, and shows four sporangia, of a cordate form, two of them being full of dark- 

 coloured sporelike bodies. The outsides of these sporangia appear to be thicker and 

 darker in colour than the generality of the specimens. Probably these differences may 

 arise from the sporangia being in a younger stage of growth. The section is outside the 

 central axis, and near to the ends of the sporangia. These dark sporelike bodies are 

 frequently met with, in a detached state, in the nodules ; but they are not often found in 

 their jjosition in the receptacle as seen in this case. The sporelike bodies also appear 

 to be larger in size than those commonly met with in ordinary sporangia. 



Pig. 4 (No. 10), magnified twenty-four diameters, represents a longitudinal section of 

 little more than a single receptacle of a cone, but it clearly shows the marked difierence 

 of the scales, both in form and structure, to the sporangium-bearers. The thick fleshy 

 bases or pedicles of the scales appear to have formed a disc- or cup-shaped division between 

 the receptacles, and to have been composed of coarse cellular tissue on the outside, 

 enveloping a bundle of pseudo-vascular tissue, which Avas prolonged into the apex of the 

 scale or leaf. The sporangium-bearers are broad at their point of connection with the 

 central axis, but they soon taper off, and form a spindle-shaped process like a thorn or 

 spine, chiefly composed of pseudo-vascular structure. Some of the sporangia contain 

 few sporelike bodies, and some are entirely empty. 



Pig. 5 (No. 11), magnified eighteen diameters, represents the most perfect longitudinal 

 section of a cone that has yet come under my observation. In it we find the structure 

 of the central axis to be of the same character as that of the pseudo-vascular bundles in 

 Cahmodendron (see p. 20 and 23), both being composed of tubes that have their walls perfo- 

 rated with oval openings. A portion of this structure, magnified 130 diameters, is shown 



