BOTANICAL GAZETTE. 105 



that this is not necessarily so, and that Sachs' and Eichler's emer- 

 gence or ligular theory may be true as to Araitcariec?, and that thus 

 the cone of these plants is really and truly a single flower. In 

 regard to Taxodinece and Cupressinem he is convinced that an inner 

 fruit scale really exists, completely adnate to the bract and soon out- 

 growing it, but he does not venture to pronounce on its nature, 

 because he thus far has no ocular demonstration of it through any 

 anamorphosis.f Professor Celakovsky concludes that the arillus of 

 Taxacece corresponds with the ligula of Araucariece. He speaks of 

 the terminal position of the ovule in this tribe as of very little mor- 

 phological importance, being really a lateral ovule pushed to the 

 top of an axis. J 



It will be of interest to those who have been misled by con- 

 trary statements, to learn that 0. Heer, the celebrated phyto-pa- 

 leontologist, has shown that geologically Abietinecs and Taxodinece 

 are the oldest conifers now known, appearing already in the Car- 

 boniferous period, while Araucariece come up much later in the 

 Trias and Jurassic formations. But relative geological age of 

 the different tribes of plants is of much less importance for the 

 appreciation of their degree of development and their position in 

 the system than some suppose. Thus the Cycadece, the Phaeno- 

 gams most closely allied to the vascular cryptogams, are, as Pro- 

 fessor Heer states, very uncertain in the Carboniferous, and make 

 their decided appearance first in the Permian rocks; therefore 

 much later than the higher developed conifers. — G. E. in Am. Jour. 

 Sri. 



Limits of Michigan Plants. — The distribution of plants along 

 the Great Lakes is a subject of much interest. The equalizing influ- 

 ence of the Lakes upon the climate of Michigan and adjacent states 

 has resulted apparentlv in bringing together the two extremes of 

 the floras considerably north and south of them. The mild 

 winters allow southern species to come in, while the cool 

 summers are favorable to the growth of more northern species. 



f The writer of this is in posession of a proliferous cone of Sequoia gigan- 

 tea which seems to prove, not only that the fruit scale in this species (and con- 

 sequently in the whole tribe) is homolgous with that of Abietinece, in so far as 

 it consists of leaves cf an axillary shoot, yet that these leaves are not a single 

 pair, but, as A. Braun has long ago suggested, in regard to Cupressinm, that 

 there is a number of leaves, laterally coordinate and connate, bearing a 

 number of ovules on their back, 



X It might be well to draw attention to the singular fact, that in the allied 

 gymnospermous family of Gnetacea, the female flower (for such it is now 

 assumed to be, the outer integument or utricle being considered as a t,wo- 

 leafed carpel) is always referred to as "terminal," whether single, double or 

 triple, while a terminal organ can not be otherwise than single. The fact is 

 that the female flowers are here axillary in the axils of one or more of the up- 

 permost bracts, and, if single, are pushed to the top of the shoot. 



