FOSSIL GYMNOSPERMS 



143 



ward. It then breaks up into about twenty smaller bundles, 

 which enter the base of the leaf." 



The ovulate inflorescence, however, is most remarkable, and 

 unlike anything known in Gymnosperms. The description 

 of Bennettites Gibsonianus given by Carruthers l and by Solms- 

 Laubach, 2 and found to apply to other forms, is as follows: The 

 strobilus is a pear-shaped body, which terminates a short axil- 

 lary shoot from the main stem, 

 and in the species cited is about 

 5 centimeters long. Only fully 

 ripened specimens, as shown by 

 the seeds, have been examined. 

 The strobilus is completely in- 

 vested by bracts, which spring 

 from the shoot and close in over 

 the apex (Fig. 98). 



An account of the details of 

 the structure is adapted from 

 Scott 6 as follows : The stalk is 

 expanded into a hemispherical 

 receptacle, on which all the or- 

 gans of the fruit are inserted. 

 From the convex surface of the 

 receptacle spring a great number 

 of slender stalks, which pass ver- 

 tically upward, or diverge slight- 

 ly toward the curved surface of 

 the fruit. Each of these stalks 

 bears at its end a single erect 

 seed, with the micropyle directed 

 outward. The seeds are so placed 



FIG. 98. Bennettites Gibsonianvs, dia- 

 gram of ovulate strobilus : re, re- 

 ceptacle ; br, ensheathing sterile 

 bracts ; s, seeds, each borne on a 

 long stalk which arises from the 

 receptacle, and in each an embryo 

 with two cotyledons ; p, dilated 

 ends of the interseminal scales, 

 which become confluent. Modi- 

 fied by SCOTT, after SOLMS-LAU- 

 BACH and POTONIE. 



that the longitudinal axis always 



meets the surface of the fruit approximately at a right angle. 

 The spaces between the stalks are packed with scales, which are 

 dilated at their distal ends, between the seeds, so as to form 

 a continuous envelop, only interrupted by narrow pits, into which 

 the seeds exactly fit. The surface of the strobilus, therefore, 

 appears as a continuous tissue, which is perforated only by the 

 micropyles of the seeds. 



The whole structure presents the appearance of a remarkably 



