106 M. Brongniart on the Relations of the 
lobed at the margins; and there is no small leaflet inserted upon 
these flattened rachides ; hence we cannot suppose that it is the 
young frond of a fern still convoluted at the extremity. I ought 
moreover to remark, that these fronds do not constitute a unique 
and exceptional case, but are extremely abundant in this stratum. 
After having compared these impressions with all the foliaceous 
organs with which I am acquainted, I find none to which they 
have more analogy than those abortive fronds, which in Cycas 
bear the organs of reproduction. These modified fronds of Cycas, 
which are much shorter than the true leayes, support on their 
base and on the two sides of the petiole, two, three or four tole- 
rably approximated ovules ; towards the extremity they expand 
into a thick lamina, which is slightly dilated and almost entire 
in Cycas circinalis, very large, and deeply cut into narrow laciniz 
in Cycas revoluta. 
There is certainly a great. difference both in the shape and de- 
tails of the form of these organs and those to which I compare 
them, but their general structure appears to me very analogous ; 
and when we recollect that the leaflets of Cycas are spirally con- 
voluted in their young state, like the lobes of this singular frond ; 
when we remember that Noggerathia, and particularly the species 
which accompanies it, has much larger leaflets than those of Cycas ; 
finally, when we find these fronds associated with leaflets having 
so many characters common to the other Cycadee, we are led to 
believe that these anomalous fronds are the abortive and fructi- 
ferous fronds of Noggerathia. This supposition is confirmed by 
the presence of large quantities of fruits, or rather seeds, which 
resemble those of Cycas most strikingly, im the same strata which 
contain these two kinds of fronds. These are large oblong or 
ellipsoidal seeds, flattened by compression, perfectly symmetri- 
cal, thicker, and as it were truncated towards the base at the 
point corresponding to the chalaza, more acute at the summit, 
and frequently towards this extremity presenting traces of an in- 
ternal body which appears to indicate the position of the micro- 
pyle and the attachment of the embryo. 5 
It is difficult to avoid being struck by the analogy in form” 
and structure of the appreciable parts of these seeds with those » 
of the Cycadee and certain Conifere, such as the yew and the 
gingko. But they present the most marked relations to the true 
Cycadee in form and size. 
Hence we find combined in a single layer of one coal-mine, 
and frequently in the same pieces of sandstone or schist :—1. 
Leaves, the leaflets of which have the form and nervation of those 
of certain existing Cycadee, especially the American Zamie ; 
2. Leaves of a peculiar form, having however a well-marked 
analogy with the modified leaves which bear the fruit in certaim 
