175 



inches long, behind which ants make their nests. Cono- 

 cephalus bears its leaves in terminal, clusters, and since seldom 

 more than five leaves are in each cluster, the ants must keep 

 moving their nests at short intervals. Species of Hydnophytum 

 and Myrmecodia are frequently seen, with large swollen tuberous 

 bases, perforated with numerous holes and inhabited by ants. 

 Since these plants are epiphytes, one can easily understand that 

 these swollen bases are organs for water storage rather than defi- 

 nite myrmecophilous adaptations. 



(To be continued) 



A SIMPLE METHOD OF MAKING CARBON LEAF 



IMPRESSIONS 



By E. D. Merrill 



With the present development of photography it is usually 

 a very simple matter to photograph any botanical specimen 

 when a graphic representation of a borrowed type, or one exam- 

 ined in some distant herbarium, is desired for future reference. 

 It sometimes happens, however, that it is not always practicable 

 to make photographs, or to have them made, in which case 

 recourse may be had to the simple, rapid, and effective method 

 of making leaf impressions indi-cated below. 



It is quite unnecessary to argue the value of graphic illustra- 

 tions of plants or parts of plants, for the utility of botanical 

 illustration is everywhere acknowledged. In a surprisingly 

 high percentage of cases the graphic outline of a characteristic 

 leaf of a type or typical specimen is of the very greatest value in 

 supplementing the published description of a species, and in 

 assisting the systematist in future identifications. In some 

 families of plants, notably in the monocotyledons, leaf outlines will 

 prove to be of little value in making ordinary determinations, and 

 the same applies to certain families and genera of dicotyledonous 

 plants. Generally, however, all broad leaved plants are adapted 

 to the method of outlining described below, and carbon rubbings 

 or impressions of such leaves are of the very greatest value in 



