216 BOTANICAL GAZETTE [SEPTEMBER - 
character. The proof of the abortion of the second cotyledon and the 
discovery of the manner in which that abortion was brought about 
naturally revive the question of the monocotyledonous ‘nature of 
certain dicotyledons. It is possible that in some cases this condition 
may be caused by the same factor which produces it in the embryo 
of Ceratozamia, but this is not so in all cases; the experimental 
work now in progress upon these forms shows that other factors are 
involved. 
The lobing at the tip of the cotyledon is suggestive of a primitive 
condition, which will be discussed in connection with Dioon spint- 
losum. 
It would be interesting to compare the cotyledonary node in all 
cycads, in order to determine whether they are modifications of the 
same type or whether there are different types; but it is a matter of 
regret that all investigators have not considered it of sufficient impor- 
tance. Marre has described it fully for Dioon edule and Cyeas 
siamensis. The latter is clearly a modification of the type Which may 
be represented by the former. The present paper shows that Cerato- 
zamia conforms to this type, and it may be in place here to say that 
Microcycas and the species of Zamia I am investigating are the 
same. WorsDELL’s Cycas revoluta and Macrozamia spiralis are 
doubtless similar. Encephalartos Barteri according to MATIE's 
description, Zamia muricata according to KarsTEN’s, and Bowen 
spectabilis according to PEARSON’s seem to differ from this tyP® 
in receiving only one bundle from the central cylinder; but there 
are two facts which conspire to make us consider that the 
of Encephalartos described by Marre was an unusual one: the 
presence of three cotyledons, and the union of the cotyledonary 
strands with the central cylinder at different levels. ie 
That cycads, especially such fernlike ones as Stangeri@ 
Bowenia, should be found to have an occasional concentric bun 
is only to be expected from the nature of their fern origin. hie: 
DELL’s announcement, then, of such bundles in the base of the oy: 
ledon of Stangeria was not a surprise, even though his are 
were not convincing. But the emphatic statement of PEARSON of 
he could not be convinced of it in WorsDELL’s preparation : 
Bowenia raises the doubt whether he would have recognized it 1p ae 
