308 N. E. BROWN, SOME NOTES ON SEEDS AS MICROSCOPIC OBJECTS. 



the best results. Place a spot-lens beneath the stage and focus 

 the light from the concave (not the flat) mirror on to the seed, 

 then with a condenser (one without blue glass) focus the light 

 upon the seed from above. This arrangement will exhibit the 

 seed in its natural tints, but if a coloured sheet of gelatine (say 

 red) is held close under the spot-lens and a sheet of another 

 colour (say green) is held over the condenser, then the beauty of 

 some of the seeds mentioned here is doubly increased and their 

 details sharpened by contrast. These coloured sheets of gelatine 

 are easily obtained from an optician at a very small cost, and I 

 believe that those who have never made use of them in the 

 manner above detailed will be pleased with the enhanced beauty 

 and probably appreciate the distinctness of detail they give to 

 many objects, such as small star-fish, etc., especially if viewed 

 under a binocular. The latter effect has been remarked by all 

 to whom I have shown this method. By reversing or varying 

 the colours employed, various charming effects may be obtained, 

 which are totally different from those produced by Mr. Hhein- 

 berg's method. In that the object is seen in only one colour, 

 surrounded by a field of another colour ; in the method here 

 detailed the object is seen in two colours upon a black back- 

 ground. This kind of illumination may not be new, but does 

 not seem to be generally known. 



As it sometimes happens that an object wanted cannot always 

 be obtained correctly named, instead of merely enumerating the 

 names of a few seeds I have added a brief descriptive note to 

 each, whereby it may be known when the right species has been 

 obtained. 



Eucharidium concinnum (Onagraceae). Select a pair of 

 seeds of equal size, mount them side by side, as above directed, 

 with that side uppermost in which a hole is present. When 

 examined you will find them to resemble a very neat pair of 

 brown " lace-up " shoes, with the margin around the top and 

 down the edges for lacing up very prettily scalloped ; tongue-piece 

 and all is represented, and the substance of the " uppers " is 

 somewhat sculptured. If a red sheet of gelatine be interposed 

 between the mirror and spot-lens and a green sheet over the 

 condenser, the soles of the shoes are outlined in red and the 

 " uppers " in green in a manner that is very effective. A native 

 of California ; cultivated in some gardens. 



Datisca cannabina (Datiscaceae). This plant has seeds 

 which resemble small bottles, covered with a coarse network. 



