The Koyal Society, London. 23 



Mr. Wild's speciraen, then, demonstrates that the Cardio- 

 carpon anomalum of Willi amson was borne on a cone with 

 all the characters of a Lepidostrobus, and that it represents the 

 matured condition of the rnegasporangiura and sporophyll. 



The detailed comparison of specimens in the young and the 

 mature condition has shown the nature of the change, which con- 

 verts the megasporangium, together with its sporophyll, into a 

 seed-like organ. The nucellus of the latter retains almost unal- 

 tered the structure of the megasporangial wall, with its columnar 

 layer. In the ^porangial cavity the single large megaspore, accom- 

 panied by its abortive sistercells, is present as before. A thiok 

 integument has, however, grown np from the sporophyll, completely 

 overarchiug the megasporangium, except for a narrow crevice left 

 open at the top. When seen in a section tangential to the stro- 

 bilus as a whole, this crevice is cut across, and presents exactly 

 the appearance of a micropyle; in reality it differs from a micro- 

 pyle in being a narrow slit, extending almost the whole length of 

 the sporangium, in the radial direction, whereas the micropyle of 

 an ordinary seed is a more or less tubulär passage. 



The integument Springs from the upper surface of the sporo- 

 phyll-pedicel ; it does not consist of the incurved margin of the 

 pedicel, for, in the more distal region, the margin of the latter 

 projects considerably beyond the insertion of the integument. 



From the frequency ot detached specimens in the Cardiocarpon 

 condition, it appears that in nature the sporophyll, bearing the 

 integumented megasporangium, was shed as a whole, though parts 

 of the sporophyll-lamina no doubt perished, only so much being 

 persistent as was necessary to form a complete envelope to 

 the „seed". 



In a strobilus associated with the seed-like specimens, and 

 bearing microsporangia, it was found that the latter, like the 

 megasporangina of the female cone, are provided with integuments. 

 This specimen was figured by Mr. Maslen as a variety of 

 Lepidostrobus Oldhamius J ), though possibly deserving specific rank, 

 a determination with which I agreed ad the time. There is 

 every reason, however, to suppose that this strobilus was a male 

 fructification of the same species, the female of which bears the 

 integumented seed-like megasporangia above described. The micro- 

 sporangial integument is more widely open than that of the mega- 

 sporangium. 



The Burntisland specimens which from their horizon are 

 presumably of a distinct species, are at present only known in the 

 isolated, Cardiocarpon condition. They are of interest for two 

 reasons: in one specimen the ligule is clearly shown, enclosed by 

 the integument, the only example of this organ, so far observed, 

 in the mature, seed-like stage of the fructification. 



Another of the Burntisland specimens is the only one as yet 



J ) Maslen, Structure of Lepidostrobus, p. 371. plate 37 fig. 21. 



