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AMERICAN JOURNAL OF BOTANY 
[Vol. 8 
could also be notable changes in flowering as related to length of life. 
Hence, even to establish the presence of a pseudomonocarpy is of deep in- 
terest. If a raceme were to lengthen out its life it would become pseudo- 
monocarpic. Evidently both mono- and pseudomonocarpy must be 
capable of variation with change in the length of life. And both, though 
in a different way, are either accompaniments of gigantism or the essential 
characteristic of communal forms. 
EXPLANATION OF PLATES 
Plate IX 
Cycadeoidea superba. A southern Black Hills trunk with five large, low subglobular 
branches, 75 centimeters across. Various sparsely distributed flower buds are noted, and 
it is quite certain that the main fruit production would have occurred later had not the 
initial event leading to fossilization intervened. The crowns have never been examined for 
the young fronds, although this form of Cycadeoidea compares most closely "with the 
highly xerophyllous Encephalartos. 
Plate X 
Portion of a slab from the Lias of the Barranca Consuelo, Oaxaca, Southern Mexico, 
bearing three species of Cycadeoids (?) : Otozamites Reglei (the three complete fronds above), 
Otozamites Juarezii (large single pinnule), and Otozamites kespera (lower frond with narrow 
pinnules). Latitude 17°. These plants with the flora associated may be taken to indicate 
a Mexican Liassic climate much like that of today, with a probability of somewhat drier, 
or even of desert and cooler conditions. Slightly reduced. 
Plate XI 
Cycadeoidea Dartoni. Portions of large sections traversing the many cones with the 
mature seeds. The dicotyledonous embryos quite fill the seed cavity, and the narrow 
slit separating the two cotyledons may be detected in many instances. Fig. i from a thin 
section. Fig. 2 from a polished surface. Enlarged. 
Plate XII 
Fig. I. Transverse section through the bisporangiate strobilus of Cycadeoidea dacoten- 
sis showing young central cone, staminate disc (with decurved frond tips), and outer bract 
husk. Enlarged. 
Fig. 2. Cycadeoidea ingens. Young non-emergent frond with folded pinnules. 
The most heavily haired frond type. The light dotted line of tissue is the pinnule, with a 
shaded band nearly as thick indicating the packed hairs. Transverse X 3. 
Fig. 3. Cycadeoidea dacotensis. Young folded frond of the lightly haired type, but 
with the bases of the cutinized hairs beautifully conserved, though not showing well under 
about fifty diameters. Transverse X 3. 
Fig. 4. Cycadeoidea ingens. Young folded frond with slight development of the 
haired feature of the pinnules. Transverse X 3. 
