BOTANICAL GAZETTE. 152 



of A.uricLilture. It makes a pamphlet of 9 pages, two being devoted 

 to "Trees," one to "Noxious Plants" and six to "Fungi on Living 

 Plants," which, of course, shows the direction of the writer's principal 

 observations. The Catal])as are noticed, and also White and Green 

 Ash and Spanish Oak. Under the head ol Noxious Plants are in- 

 cluded whit we loosely call "weeds." Some of the most pestiferous 

 are mentioned and especial attention called to the fact of their won- 

 derful fecundity. The part on Parasitic Fungi is by far the most im- 

 portant as it gives some account of a group ot organisms very import- 

 ant to farmers and very little understood. 



On the Development of Lonna minor. — This is a four-page pam- 

 phlet with plate, reprinted from the Proc. Acad. Nat. Sci. of Phila. 

 The author. Mr. Wm Barieck, had his attention called to the 

 so called "bulblets" and after careful investigation has come to the 

 conclusion that they are in reality regular seeds, from which, howcer, 

 the fronds are projjagated in a peculiar and interesting manner. The 

 fiufilres iiiven are taken from sections which he has mounted and hence 

 may be c(;mpared at any time. The closing sentence gives the 

 author's conclusions. "My investigation has been made only on the 

 Lemiia minor, but theie is no reason to doubt that in the develoj)ment 

 of the whole family of Lcmiiaeae (analogous to our species) we have 

 an interesting instance of ])arthenogenesis, there being seeds (produced 

 in autumn by a sexual process) from which, during the course of the 

 summer, generation after generation is propagated without any further 

 fertilization." 



On the Timber Line of Hii^^h Mountains. — Mr. Thos. Meehan in a 

 paper before the Acad. Sci. of Phil, upon this subject, came to the 

 following conclusion : 



In view of the facts detailed we may conclude that at the eleva- 

 tion of these mountain chains, the lowland vegetation was carried up 

 at the same time. The summits, covered by luxuriant forests would 

 present a cooler surface to the moist clouds, and there would be less 

 condensation than on bare sun warmed rocks, and deep snows would 

 be less frequent, and not sufficient to interfere much with arboreal 

 growth. But the rain would of necessity carry down the earth and 

 disintegrated rock to 1 )wer levels; and the melting snows, such as 

 there were, would make this downward progress of the soil continu 

 ous. In some mountains where the rock was easily broken by frost, 

 as in Colorado and the White Mountains, it would be very difficult 

 for the soil to hold its own against these forces of gravitation ; but on 

 more solid rock the mass of tree roots protecting the rock, and re- 

 taining the earthy matter would longer hold its own. In the former 

 case with the gradual washing away of the earth the larger trees will 

 have to find a lower level ; the summit condensing more moisture, and 

 having a cooler atmosphere, would form heavier masses of longer 

 enduring snow, and thus keep down from tall growth the younger 

 trees lett as the older and larger ones retired. They would have to 

 be low bushes by the absence of earth for vigorous growth, and remain 



