ECOLOGY. 293 



when transplants are made in the fall, which is the preferred time. A 

 detailed record is made of the transfers and each plant is labeled in 

 such a manner as to indicate its source as well as its reciprocal. Type 

 specimens have also been preserved for comparison and histological 

 material obtained for studies of leaf and stem adaptation. 



Variation and Mutation in Epilohium, by Edith Clements. 



This is a continuation of researches carried on in the field and 

 greenhouse from 1902 to 1905 to throw light upon the origin of new 

 forms and the relation between variation and mutation. Epilohium 

 spicatum was chosen for this work because of the large number of flower 

 and rosette modifications it exhibits, as well as on account of its adap- 

 tability to a wide range of habitats. In the early work an unusual 

 number of apparent flower and rosette mutants was secured. Some 

 of these were grown under measured control to determine their range 

 of variation, and others under uniform conditions to ascertain whether 

 the characters could be accumulated and fixed. The present study 

 is being conducted along similar lines, but is devoted especially to 

 the isolation of pure lines and to the experimental production of mu- 

 tants. The production of flower mutation by manipulating the flow 

 of food to different parts through pruning, mutilation, change of posi- 

 tion, correlation, etc., has proved unusually successful. It is planned 

 to grow these during the year to determine the extent to which such 

 artificial mutants are fixed or are capable of being fixed. 



Experimental Pollination, by F. E. Clements and Frances Long. 



Considerable progress has been made in extending the experimental 

 studies of flowers and insects begun in 1912. A method of experi- 

 ment has been devised for the purpose of testing the mutual responses 

 of flowers and insects, many of which have heretofore been accepted 

 upon the basis of mere observation. This method has grown out of 

 several summers' study of the life-history and pollination behavior 

 of the flowers of 70 species. It consists of a number of experimental 

 devices for testing the value of various floral structures and char- 

 acters, as well as the perception and habits of pollinators. These 

 fall into a number of categories, of which the following are the most 

 important: (1) changes of flower or plant position, or of the time of 

 blooming; (2) transfer of flowers to plants of different floral type and 

 the use of mixed field bouquets; (3) changes in the color of the corolla 

 by painting or masking; (4) changes in the position of petals, sepals, 

 stamens, styles, staminoids, and nectaries, and hence often in the 

 shape of the flower; (5) changes by removal or mutilation of parts, 

 such as cutting a tubular corolla into its original parts; (6) addition 

 of parts or of extraneous substances, such as honey, perfume, etc.; 



