4 Hick, on Rachiopteris cylindrica, Will. 



longitudinally. In the middle part of the cortex, where 

 the hypoderma and the inner parenchyma run into one 

 another, the cell walls are thinner and often much 

 crumpled. In young specimens a complete zone of 

 thin-walled elements occupies this region, but in older 

 ones it is occupied by a series of radial lacunae, separated 

 by cellular partitions. (Fig. i.) From the appearance 

 of the tissues abutting on these lacunae, it seems probable 

 that their origin was lysigenous rather than schizogenous. 



The contents of the cortical elements are somewhat 

 remarkable, and present some interesting modifications. 

 In one or two specimens the contents of both hypoderma 

 and inner parenchyma are in the form of contracted 

 utricules, as may be seen in the marginal section on 

 No. 102. But in the second section on the same 

 preparation, as well as in other cases, the utricular form 

 is restricted to the hypoderma, and the contents of the 

 inner parenchyma are in the form of granules, which 

 remind us of the stored starch of recent plants. In the 

 majority of the preparations, however, the cortical cells 

 contain certain sharply defined black bodies, of a rounded 

 or ellipsoidal shape, and with an even contour (Fig. 2). 

 Frequently they are seen to be enclosed in a sort of 

 vesicle, the cavity of which they do not fill, and whose 

 wall is, therefore, somewhat removed from the body itself. 

 The bodies are small compared with the size of the 

 elements in which they lie, and two or more are frequently 

 seen in the same element, especially in longitudinal sections 

 like No. 113. In the specimen figured by Williamson* 

 they are very numerous, and are carefully represented, but 

 are not referred to in the description. In most instances 

 where the black bodies are present, the granular and 

 utricular forms of cell contents are absent, but not in all. 

 Thus, in No. 115 the contents of the hypoderma are 



*Loc. cit. Plate XXIV., Fig. 80. 



