87 



VARIATION 



. In connection with advanced biolog>^ work the laboratory' 

 study of material illustrative of variation has been found useful. 

 For the fluctuating variation the ordinary "yellow-eyed" bean 

 of the seedsman furnishes material in which intergrading series 

 showing variation in the size of the pigmented spot, of the 

 depth of color of the spot, as well as of the total size of the bean, 

 are easily discovered by the pupil. Material for mutation is 

 easily obtainable in the form of some of the definite sports of 

 the Boston fern series. The distinct differences of these bud 

 variations are represented in separate pinnae and these latter 

 furnish objects for representation by the pupil entirely within 

 his ability to draw in a short time. A single laboratory lesson 

 on variation may include both the fluctuation and the mutation 

 types. 



HABITATS 



The topic of the adaptation of plants to different habitats 

 always occupies a considerable place in high school biology, 

 especially in the more advanced courses. Pupils of Stuyvesant 

 High School to the number of 150 or more visit the Brooklyn 

 Botanic Garden each term in connection with their term's 

 work in plant study and, in groups of about 30, are shown the 

 characteristics and adaptations of plants arranged under six 

 habitat groups: — 



(i) Xerophytes. 



(2) Hydrophytes. 



(3) Epiphytes. 



(4) Insectivorous plants. 



(5) Parasites and saprophytes are also included in the dis- 

 cussion though the illustrative material for these latter is 

 not usually available. 



Further in connection with this field trip the attention of 

 the pupils is called to characteristic examples, and general 

 economic importance of six main groups of plants, broadly 

 classified as phyla, viz.: bacteria, fungi, algae, mosses, ferns 

 and seed plants. The special display of plants arranged to 

 show the probable evolutionary development of the difTerent 

 types at the Brooklyn Botanic Garden, house No. 2, makes 

 a particularly good station for a description of plant phyla. 



