﻿128 REPRODUCTIVE STRUCTURES. 



type of the present species. This fine trunk bears ovulate strobili more profusely 

 than any other of its kind yet discovered (189). It appears, from the eccentric posi- 

 tion of the xylem at the base and the appression of the leaf bases on the side nearest 

 the xylem, to have been a low-growing branch, or else one of a clump of branch- 

 like trunks. The crown is entirely broken away, the recovered portion having 

 a length of 30 cm., a long diameter of 25 cm., and a short diameter of 20 cm. 

 Notwithstanding this small size, this trunk bore embedded in its armor at the time 

 of its fossilizatiou no less than seventy-seven fruits of about the same stage of 

 growth as those just described in trunk 393. Moreover, of these seventy-seven 

 fruits no less than forty-three are still actually present and bear all or a portion of 

 their seeds. A few are still quite surrounded by bracts, but usually the tips of the 

 bracts have failed of preservation and likewise the outer pericarp of expanded inter- 

 seminal scales, the seed layer thus being exposed in most instances. There is, 

 however, one fortunate exception. One of the larger fruits projects well beyond 

 the armor and is quite complete. On the surface of its pericarp the terminal ends 

 of the micropylar tubes and the patterns formed by the surrouuding scale tips are 

 all preserved with delicate exactness of outline. 



As showing how profusely the old leaf bases produced these lateral axillary 

 strobili it may be noted that the most favorably located one-eighth part of the whole 

 surface bears twenty-two fruits. Had all the surface been equally prolific the plant 

 would hence have borne upwards of one hundred and fifty strobili. But in addition 

 to the seventy-seven larger strobili present there are only a very few, perhaps three 

 or four, young strobili, wdiich, as in the previous case, may either have been abortive 

 or may have matured during a succeeding season had the plant continued to grow. 

 Taken in conjunction with the preceding instance it would, however, surely seem 

 quite as likely that these few smaller axes were abortive, and that the wonderful 

 series of fruits here preserved represented the culminant effort of the plant — an effort 

 which, had not the exigencies resulting in silicification intervened, would have been 

 followed by death as in Corypha. There is in this immediate connection one other 

 exceedingly interesting specimen, which indicates that at least some of these plants 

 did not produce fruits until late in life. In this cyead, No. 76 -f- 375, a portion of a 

 distinctly columnar trunk, shown in plate v, photograph 5, the beautiful regularity 

 of the old leaf bases is undisturbed, save by a single small seed-bearing fruit, and it 

 is perfectly clear that the part of the trunk preserved never bore any other than 

 this single fruit shown in longitudinal section (plate xxv, photograph 1). Of course 

 the unknown summit may have borne many fruits, but such a fact would only add 

 strength to the idea here suggested that the trunks of the species before us only 

 bore fruits late in life, and then mainly but for a single season, or at least only with 

 strongly diminished activity the second season. Almost the only feature that might 

 be thought to militate agaiust such a view is the slightly greater number of fruits 

 usually found on the upper half of these trunks. But the difference in this respect 

 is not great, since considerably more than a third of all the fruits of cycad 77 are 

 borne on the lower half, where very naturally there is less freedom of late growth 

 of either fruits or adventitious foliage. 



