IOWA ACADEMY OP SOIKNCES. 153 



The work of Clements and Pounds views the subject 

 fmm a broad standpoint, giving also minute details of the 

 plant formations.* In a more recent paper thev have 

 extended their work to more local conditions.f The chief 

 center of this line of work in this country has been at the 

 Univeisity of Chicngo, where Cowles:|: "iind students of 

 Prof. Coulter have devoted themselves assiduously to a 

 study of the many intricate problems, problems "by no 

 means easy as shown by Cowles. 



During the summer and fall two important papers on 

 this subject have appealed, one by Dr. Brav: on tlie ecolog- 

 ical relations of the vegetation of western Texas, a regio"ii 

 well worked by botanists and a choice field for botai"ical 

 investigation. The richness of the flora became known 

 through Wright, Lindheimer, Fmidler, culminating in the 

 large Flora of Western Texas by Coulter.i,< 



While these men discussed the generartioristic features 

 of so interesting a region but little was known of the bio- 

 logical relations of these j^Iants. The paper takes up (1) 

 the climatic and edaphic factors, (2) physiographv and 

 geology, (3) plant formations. 



The main divisions of plant formations are grouped 

 under 



(I. Grass formations. 

 h. Woody formations. 



c. Succulent formations. 



d. Halophytic formations. 



It is unnecessary in this connection to enter into details 

 of the subdivisions of each, though important in inter- 

 preting the character of the plants and their relation to 

 the general features of the flora. 



Dr.Charles Mohr,** the well known botanist of Alabama 

 left as a mo nument to his many years of labor in Alabama 



Pl. l^^TlTf ""'^ ^°""'^''^- ^^^ Pl^ytogeography of Nebraska Gen. Sur. Ntbr. .14Z 

 .tJ^^k^^. "1^ ^tev.^'of N?,?rB*orSnrv^T"* C°"-"°-- studios in the V.g- 

 igan.^ "B^l'^Gaz^^^'Ef • "'FS 1'^ 36? V^"" "^^'S^^^^^oi^ in the Sand-dunes of Lnke Mich- 

 105, 'S"24T^?fKJr' Con^riJi^ fe ^fb^^^" '' --*-° Texas. Bot. Gazette 32: 9D. 



"^PlanTnf.^nT^A'l",'^''^^-- **^°"*'"- U- S.' Nat. Herb. 2: 18f»l-4 

 adaptSl of ho'fltrfriiabtmrtSher wrt>f'''"'".^"«";-'"^^^^^^«f a.ssociatioM and 

 growing in «.e state. C^^t^'S^a-^^^fe ^S. D^'^ Agrr^^^ l./fi. ""^^ 



