168 



2. The number of the specimens returned will be at the dis- 

 cretion of the Director, and will depend on the rarity and condi- 

 tion of those furnished. In the case of well-known plants they 



I 



will probably nearly equal the number sent. 



3. In the case of small plants, several specimens should be 

 furnished under one number, as in such cases a single specmien 

 is not a satisfactory representation of the species. 



4. Specimens may be called for by species or genera or by 

 the locality from which they are wanted. To save time the 

 species may be indicated by the numbers which they bear in any 

 well-known American catalogue, the name and the edition 01 

 the catalogue being given. 



5. Specimens sent must be accurately named and bear the 

 date and locality of collecting, with the name of collector. Little 

 value will be attached to specimens which are imperfect or poorly 

 prepared. 



6. The Director of the Exchangre will, reserve the right to in- 



dicate his judgment in cases where specimens seem improperly 

 named, but the responsibility of the names will in other cases 

 rest with the original sender. 



7. For the present, well prepared specimens of all phaenoga- 

 mous and higher cryptogamous plants will be received, and also 

 specimens of thallophytes, the last mentioned to be In charge of 

 the Chief of the Section of Vegetable Pathology. Hereafter lists 

 will be published of plants especially desired or of which no more 

 specimens are needed. 



8. An account of the specimens received from each person 

 will be kept, and of those sent in return, and also of any other 

 specimens which he desires or can supply. The Exchange w 

 thus serve as a bureau of information upon this subject. 



9. Conditions of membership : 

 Any botanist may become a member of the Exchange Club 



by paying annually to the Director the sum of two dollars, this 

 money to be used in payment for postage, printing and inciden- 

 tal expenses. 



10. Address specimens and communications to the Director 

 of the Exchange. 



ill 



t. 



Dr. Geo. Vasey, 



Botanist Department Agriadtiire^ Washington^ D. C 



