MISSOURI BOTANICAL GARDEN BUI I.KTIX 15 



Mounting and Distribution. — The mounting of herbarium 

 material has continued throughout the year ; and nearly 15,000 

 mounted specimens have been added to the organized her- 

 barium. Much time has been devoted to the sorting and dis- 

 tribution of specimens in order to render the collections more 

 readily available and of greater service to the investigator. 



Field Work. — Systematic field work in the Southwest was 

 again discontinued this year, but through cooperation with 

 the Arnold Arboretum a complete series of the valuable col- 

 lections made by Mr. Ernest J. Palmer in the Ohio and Mis- 

 sissippi River Valleys has been secured. Through a cooper- 

 ative arrangement between the University of Wyoming and 

 the Garden herbarium Mr. and Mrs. E. B. Payson spent about 

 two months in the field mainly in northwestern Wyoming and 

 adjacent Idaho from which an excellent series of herbarium 

 specimens was obtained. These plants are of especial inter- 

 est since they come from a comparatively little explored region 

 and since they greatly augment rather fragmentary collections 

 made by Henry Engelmann on one of the early government 

 surveys. Local field work has been carried on to a limited 

 extent; and numerous friends of the Garden have deposited 

 in the herbarium local collections of special interest. 



Exchanges. — A number of important series of herbarium 

 specimens have been acquired from institutions with which 

 the Garden maintains exchange relations. A comparatively 

 small number of duplicates, however, lias been sent out during 

 the year. 



Use of the Herbarium by Outside Botanists. — The number 

 of visiting botanists who have consulted the herbarium during 

 the year is again relatively large ; and every facility possible 

 has been extended to the visiting specialist. It has been nec- 

 essary to further limit the loan of herbarium material, be- 

 cause of frequent fragmentation of specimens and the undue 

 amount of salaried time required to draw out and carefully 

 record the specimens loaned as well as the redistribution of 

 them upon their return. A few small loans have been made 

 to a very decided mutual advantage. Dr. Norma E. Pfeiffer. 

 of the University of North Dakota, spent some time at the 

 herbarium during the past summer in pursuance of her mon- 

 ographic study of Isoetes. This w^ork will probably be ready 

 for publication some time during the coming year. 



