310 



SCIENCE 



[N. S. Vol. XXXIII. No. 843 



case which the present writer has used with 

 much satisfaction. 



The mount consists of a rectangular, wooden 

 frame of any desired size (e. g., 10 X 12 

 inches) made of pine strips three eighths of an 

 inch square in thickness, mitered or mortised 

 at the corners, holding apart two sheets of 

 glass corresponding in size to the outer edge of 

 the frame, one for the top and one for the bot- 

 tom of the mount, which is bound together 

 with passe-partout 11 inch wide. As for the 

 glass, old photographic plates, 10 X 12 inches 

 in size, cleaned with caustic potash solution, 

 are convenient in dimensions, thin and light, 

 and of good quality. 



Each butterfly is prepared by stretching and 

 drying it upon its dorsal surface, pinning it 

 temporarily until it has been made fast with 

 strips of paper. The wings of the dried speci- 

 men must lie flat, or be inclined slightly ven- 

 trad, but never dorsad. It is then fastened, 

 with a small drop of thin liquid glue applied 

 to the dorsal surface of the thorax, to the sheet 

 of glass that is used as the upper pane or 

 cover. Small strips of sheet lead (about 1 

 inch X 14 inches), bent into an arch, make a 

 convenient weight to set astride the wings 

 until the specimen is well fastened to the 

 glass. The pane is then inverted over the 

 frame, and glued to it. The lower sheet should 

 not be glued to the frame, but fastened to it 

 only by the strip of passe-partout, li inch 

 wide, which is used to hold the two panes of 

 glass together and seal the mount. If a 

 specimen should get loose, the bottom glass 

 may be easily cut away, repairs made, and the 

 case sealed with fresh passepartout. If the 

 upper pane should get broken, it is a simple 

 matter to remove the specimens, using steam 

 when necessary, and remount them. Care 

 should be taken in the preliminary stretching 

 of the specimens lest the feet should project 

 more than necessary, so that, when the case is 

 put together, they come into contact with the 

 lower plate, and loosen the attachment to the 

 upper. For ordinary purposes, however, it is 

 only necessary to trim off the tips of a few 

 that project excessively. 



Seven hundred butterflies of the size of 



Colias philodice can be filed away in the space 

 of a single cubic foot, in the mounting frames 

 just described, each case measuring 10 X 12 

 inches in breadth and length and one half 

 inch in thickness, and containing 25 speci- 

 mens. They are sealed from dust and vermin, 

 and easily examined on both surfaces in 

 groups of convenient size. 



A rich field for conquest awaits any one who 

 chooses to leave the beaten tracks of en- 

 tomology and scout among the fastnesses of 

 experimental evolution. When one considers 

 the remarkable results that have been accom- 

 plished single handed by such observers as 

 Standfuss, Tower, Doncaster and T. H. Mor- 

 gan, not to mention many others, the possi- 

 bilities achieved in this field if the huge 

 army of observers already interested in insects 

 should attack in an organized way the prob- 

 lems of variation, the inheritance of acquired 

 characters, mutation and natural selection, 

 polymorphism and sex, mimicry and protective 

 resemblance, can hardly be overestimated. 

 Desultory observations of the strolling natural- 

 ist will not help much in this conquest, but 

 long-continued breeding of carefully selected 

 strains under well-controlled conditions can 

 not fail to win valuable results. 



Entomological societies and journals of the 

 future, in order to contribute effectively to the 

 real advancement of science should organize 

 cooperative plans of research along these lines, 

 and enlist the services of the countless obser- 

 vers whose random notes now fill their 

 archives. John H. Gerould 



* VAHIEGATION OP EUROPEAN ALFALFAS 



As a part of the extensive investigations 

 being conducted with alfalfa at the Dickin- 

 son, North Dakota Sub-station, a series of 

 European alfalfas was planted in the nursery 

 in 1909. A study of some of the plants in 

 1910 revealed the presence of variegation in 

 flower coloring. This was expected to a cer- 

 tain extent. As a preliminary to the determi- 

 nation of the correlation of the variegation to 

 other characters, both physiological and 

 morphological, the percentage of variegation 

 was determined for each strain or planting. 



