303 
Cycas should be homologous with the cupule of Lage- 
nostoma, and that the testa of the Cycads should be 
composed of two originally free layers accordingly. 
And as the sarcotesta of Cycas belongs to a true 
integument she calls the cupule of Lagenostoma an outer 
integument. We have seen that the cupule of Lageno- 
stoma does not appear to be an integument, but as long 
as we do not know this accurately, we may certainly 
not homologize it with an organ, that is much higher 
specialized and give it the same name. Besides, the 
differentiation into the three layers, occurring in those 
organs too, which have arisen undoubtedly from a single 
whorl of units, as in Trigonocarpus, Ginkgo a. o., there 
is no reason to speak of a double origin, only on account 
of a probable resemblance in orientation of the vascular 
bundles. 
Salisbur y (127) has already published about the relation 
between Ginkgo and Trigonocarpus. Here Ï may add a 
point of apparent resemblance, which Salisbury did not 
notice, viz. the clearly visible sutures at the places of the 
ribs in the apical region in a young stage of development 
of the ovule of Ginkgo (fig. 6). These sutures support the 
view of possible connection between the seeds of Ginkgo 
and Trigonocarpus, which had been supposed by the 
great frequention of three-angular seeds, investigated by 
Affourtit and La Rivière (1). 
This feature is also exhibited more or less in all the 
other gymnospermous seeds. The occurrence of two, 
three, four or five ribs on the stony coat is a very common 
thing. For Cupressus (140), Pinus (64) and Ephedra (51) 
it has been observed that the integument originates as two 
separate papillae between which a third one, the nucellus. 
Undoubtedly it occurs also that the integument is formed 
of three or more projections, but till now no great atten- 
tion has been paid to it, otherwise it would not have 
