﻿140 REPRODUCTIVE STRUCTURES. 



yielded is so beset by doubt as to be of no great importance, and will require future 

 verification and extension, based on fortunate discoveries which, I believe, will not be 

 wanting. Nevertheless, I hold it somewhat to the purpose to describe the conditions 

 as found. 



' ' The best section obtained is like that shown in T. iv, figure 1 . It is the exactly 

 median longitudinal section of an inflorescence of Cycadcoidea etrusca, and was fortu- 

 nately exposed by the ver)' first cutting, as made at Florence in the Royal Manufactory 

 for Works in Hard Stone. It is to be seen on the polished surface of the original 

 specimen at the Geological Museum of Bologna. From the other half of the same 

 I had a thin section made which is represented in the above figure. One sees 

 that the shoot had a thick and fleshy axis surrounded by scale-like sepalaceous 

 leaves. The tissue of the axis is wholly destroyed; and of its leaves or bracts only 

 the dense masses of ramentum are preserved, these being, as seen in longitudinal sec- 

 tions, traversed by structureless striae, representing the original ramentum-bearing 

 scale leaves. The receptacle after becoming slightly smaller ends in an ovoid and 

 slightly pointed spadix 1 cm. in length and 7 mm. in its greatest diameter, the 

 fleshy substance of which has likewise been destroyed. Above this spadix is to be 

 seen a small free space filled with some sort of fragments to be mentioned later. A 

 little beyond, the ramentum of the sepalaceous leaves closes in from all sides as a 

 compact mass of considerable thickness, in which the irregular sections of the sepa- 

 rate obliquely cut leaves appear as gaps. No communication exists between the space 

 above the spadix and the exterior, though in the successive sections made from other 

 floral shoots from the same specimen such must have been observed, if present. The 

 entire surface of the spadix is enveloped by a layer a little more than a millimeter in 

 thickness, which is composed of numerous parallel structures always standing verti- 

 cally to the outer surface. These arise as separate cylindrical rods whose extremities 

 spread out tuft-like and form a continuous surface. The transverse sections of these 

 structures show here and there traces of tracheal tissue, which are, however, very 

 indistinctly preserved. But in any case it is not to be doubted that we have here 

 sexual organs closely appressed in a thick-set layer, and covering the terminus of a 

 spadiciform receptacle. This is also confirmed by the study of transverse sections of 

 the same organ, some of which were cut through the apex of the spadix, in which the 

 structures may also be seen in oblique section. The representation of such a section 

 is given in T. v, figure 4. It shows centrally the tip of the receptacle, with the rod- 

 like radiating bodies which form the outer layer cut obliquely. In this section one 

 recognizes numerous circular forms filling the gaps in some continuous mass of dark- 

 brown color. These forms show a compact outer zone inclosing the much-altered 

 remains of a feeble-walled tissue. Recalling now the structure of BennetUtes, one is 

 tempted to regard the organs of circular section as female, their supports as "cords" 

 or seed stems, and the surrounding tissue mass as the interstitial tissue which exteri- 

 orly spreads out into a continuous layer inclosing the seeds or seed spaces. The entire 

 stratum of flowers, in case this combination represents the actual condition, would at 

 maturity have grown much larger, if it can be compared with the mass of pedun- 

 cles, interstitial forms, and seeds, as borne by the receptacular cushion of BennelHtes 

 Gibsonianus . 



" In the small inclosed space between the extremities of the central spadix and the 

 inbending tips of the sepalaceous leaf scales, as above described, occur several further 

 tissue forms which must for a moment occupy our attention. Here there are several 

 irregularly shaped lobes of elongate form, consisting of lengthened cells, upon which 

 lie scattered in every direction great numbers of little bodies of a peculiar form 

 (T. 4, fig. 1 , at a). Any of these enlarged appear at first like a pair of needles pointed 



