BOTANICAL GAZETTE. 39 



and other facts point to a recent origin of the pine forests under 

 consideration, which might not have been in existence at the time 

 of the landing of Columbus. This fact is more apparent when it 

 is stated in this connection that the average age of the pine is less 

 than three hundred years in this country; and the other fact is reit- 

 erated that it does not reproduce on the same soil. The present 

 pine forests, then, doubtless took the place of some other species, 

 which had exhausted the soil necessary to their existence, a phe- 

 nomenon well known to naturalists. It matters not whether the 

 seeds were blown there by the winds, or lay dormant in the soil 

 until their turn, or, indeed, what the speculation concerning them 

 is, so long as the facts are inaccessible; certain it is the origin of the 

 pine forests in Michigan is a matter of several centuries ago. 



Ueber die weiblichen Bluethen der Coniferen, von A. W. 



Eichler, Berlin, 1881 (a pamphlet of 32 octavo pages, and a double 

 plate). — In this interesting paper Professor Eichler frankly avows 

 that his views respecting the female flowers of Coniferae have un- 

 dergone some important changes since the publication of his Blue- 

 thendiagrainme. The views now held are, as he states, essentially 

 those found in Sachs 1 Lehrbuch, but he adduces copious illustrations 

 in support of them, and adds a succinct history of the controversy 

 regarding gymnospermy. Since the time of Robert Brown most 

 botanists have held that the ovules of Coniferae are naked, while a 

 few have considered them as ovaries with single ovules. The main 

 point, however, in the late discussions has been with respect to the 

 nature of the bodies, often scale-like, from which in most cases the 

 ovular structures arise. Notwithstanding their flatness, the scales 

 have been looked upon by some as axial in their character; by oth- 

 ers as leaves and hence carpellary. From the short extract which 

 is translated below it will be seen that the author does not regard 

 it as impossible to harmonize the conflicting views, at least in part. 

 " In all Coniferae, the scales of the so-called female anient represent 

 nothing but simple leaves; the inner scales,where they are met with, 

 being ventral outgrowths therefrom. The ovules take their origin eith- 

 er on the inner surface of these leaves or in their axils (in Taxus and 

 Torreija only, they appear at the apex of a special bracted axis. In 

 these two genera the ovules are to be regarded as female flowers ; in 

 all the other genera the ament represents collectively the individ- 

 ual female flowers, the leaves being open carpels.). At first sight 

 there appear to be important morphological differences which, in a 

 family so conspicuously natural as Coniferae, we should not expect 

 to find. Thus in one case the ovule seems to be an appendage of the 

 leaf, in another, axillary and therefore seemingly an axillary shoot, 

 and, thirdlv, a body at the er^d of a leafy axis. But these differ- 

 ences are not so great as they appear. The ovule has the character 

 of a macrosporangium, and "may perhaps rightly bear this name, as 

 many have proposed. Therefore, what we see realized 111 a macro- 



