n6 



STUDIES IN FOSSIL BOTANY 



portion was quite short. The general direction of the 

 whole organ was horizontal (see diagram, Fig. 49). 



^-&c 



Ace. 



Fig. 49. — Cheirostrobus petty ctirensis. Diagram. The upper part in transverse, the 

 lower in radial section ; the position of the organs corresponds in the two sections. 



ju Transverse section. Six complete sporophylls, each with three segments, are shown. 

 Sfi.a. , section passing through sterile segments ; Sj>.b. , do. through fertile segments or 

 sporangiophores ; st, lamina of sterile segment ; st\, downward outgrowths of sterile 

 laminae, cut transversely ; st%, their apices, transverse ;_/J peltate sporangiophores ; sni, 

 sporangia. Note that in Sjb.a. each peltate lamina, f, is seen in two distinct lobes, 

 with the sterile lamina between. v.b.\, v.b.%, vascular bundles of two whorls. 



2. Radial section. The sporophylls are separated from one another for clearness' sake ; 

 in nature they are in close contact. Ax., axis of cone ; cy, its stele ; J>k, base of 

 sporophyll. Other lettering as in transverse section. The diagram is true to nature 

 as regards proportions of parts, as well as their relative position. X about 2. 

 Phil. Trans. } S. 



The segments of each sporophyll were of two kinds, 

 the one set fertile, bearing the sporangia, the other 



