PALAEONTOLOGY. 397 



some rare occurrence of many examples at a restricted point could yield the 

 final data. But the numerical relation between young leaf-crowns to the old 

 leaf series in forms not distinctly monocarpic may be considered, as well as 

 a slight tendency to form growth rings. The types were long-lived, and it 

 can therefore be asserted only that the monocarpic character was developed 

 to such an extent that it could readily become regional in both these and 

 related plants. These studies hence emphasize the fact that monocarpy is 

 progressive in its origin, varied of phase, ecologic in significance, and until 

 recently much in need of redefinition by botanists. 



Thus is outlined the first expression of monocarpy discovered in the gymno- 

 sperms, and of course the only instance recognized in ancient plants. It 

 means much. The cycadeoids had a varied unisexual and bisexual floral 

 development, and they reached their very highest degree of specialization in 

 the monocarpic type. Culminant fruiting, in fact, developed in the widely 

 distributed, specialized, long-lived type, in as pronounced form as in the 

 modern bamboos. The more readily could the habitus characterize innumer- 

 able less conspicuous, generalized relatives. Such we have every right to 

 hypothesize in tens of thousands of species. 



While, then, the monocarpic cycadeoids are as stubbornly specialized as 

 any gymnosperms in their vegetative features, a definite monocarpic trend 

 quite unexpectedly indicates a high range of plasticity. Other slender- 

 stemmed and branched types or their dwarf relatives would everywhere come 

 under the average soil and moisture conditions of the copse, or of the more 

 open scrub or bushy to grassland association — the lesser vegetation more or 

 less antecedent to early dicotyl development. For an early presence of 

 monocarpy is not only thus established, but even the factors which produced 

 it come into view. 



Here, too, are other possibilities, additional explanations of how readily 

 the early cycadeoids could modify in the direction of the present-day seed- 

 plant dominants. With perhaps much of reduction in many instances, the 

 rise of the simpler monocarpic dicotyls, the annuals and biennials, would thus 

 always be coordinated with the forest-forming perennials, in all formations 

 and successions. It follows, moreover, that any hypothesis of dicotyl deriva- 

 tion from the coniferales rather than the cycadeoids, should be based on evi- 

 dence of widespread occurrence in the early Mesozoic of bisexual coniferous 

 flowers, and at least some indications of a prevailing monocarpic tendency. 

 So far such evidence within the coniferales is notable for its absence. 



Another year has passed without direct university cooperation in these 

 elaborations of important material, but the Washburn College at Topeka, 

 Kansas, forwarded for examination a singularly unique cone or head attached 

 to its stem, from the lower Cretaceous of Ellsworth or an adjacent county. 

 This is described along with some other material in a Bulletin of the Canadian 

 Geological Survey shortly to appear. The Harvey Lewis Company of New 

 Haven, mentioned in last year's report, has given further aid on thin sections. 



Efforts extending over several years to have the great Minnekahta cycad 

 locality segregated and protected because of its extreme scientific and gen- 

 eral interest and value can now be reported as successful. President Hard- 

 ing has recently signed and sent to the State Department the proclamation 

 for the creation of the Fossil Cycad National Monument of South Dakota. 



