688 



SCIENCE 



[N. S. Vol. XXXI. No. 801 



Ever-sporting varieties may be illus- 

 trated by such races as the five-leaved 

 clover of de Vries and his fasciated teasel. 

 The theory of mutation can not be better 

 illustrated than by the classical example of 

 Lamarck's evening pi-imrose with some of 

 its most striking mutants. 



Hybridization, as one of the most impor- 

 tant means of effecting changes in combina- 

 tion of plant characters, demands a promi- 

 nent consideration in the section of the 

 garden under discussion. Mendel 's law can 

 perhaps best be shown by hybrids between 

 white- and scarlet-flowered races of a free- 

 blooming species like the scarlet runner 

 l)ean in which the color characters are evi- 

 dent in vegetative as well as in floral parts, 

 and the assumption of color factors is not 

 necessary to explain the color relations of 

 the offspring. If suitable examples can be 

 obtained, blend and mosaic hybrids might 

 also be illustrated. 



Due to hybridization and other causes, 

 the sexually formed seed can not be de- 

 pended upon to reproduce the characters 

 of the parents without change. Vegetative 

 means of reproduction such as cuttings, 

 since they merely increase the individual 

 plant, do, however, reproduce individual 

 characters. Sowings from seeds and roots 

 respectively, from a single plant of some 

 modern type of dahlia would show the 

 truth of the saying, that cuttings come 

 true, but seedlings do not. 



It has been the writer's practise to have 

 each student choose some single plant for 

 personal investigation to find out from the 

 plant itself as much as possible without 

 unfavorable prejudice from literature. The 

 amount of work has been largely voluntary 

 and a reasonable proportion of the students 

 have responded to the suggestions offered 

 them for this elementary research work. 

 A portion of the garden is reserved for 

 carrying out cultures and experiments, 



which the students themselves may suggest, 

 in connection with their plants under in- 

 vestigation. 



The special type of botanic garden which 

 has thus been outlined by specific examples 

 is the outgrowth of the needs of a teaching 

 botanist in an agricultural institution. It 

 has furnished material for demonstration 

 purposes, for laboratory exercises and for 

 field observations. Its systematic section 

 being built on the plan of the pocket dic- 

 tionary with the m»st used forms repre- 

 sented has been considered as forming a 

 not unnatural basis of a student's list of 

 recognizable plants, and accordingly ability 

 to identify the species grown in the gar- 

 den has been expected of students taking 

 botany. 



Though the chief function of the agricul- 

 tural botanic garden may be considered as 

 being instructional for special courses, it 

 should prove of interest to students out- 

 side their classes and to a visiting public. 

 It may, therefore, be not inappropriately 

 termed a field museum of agriculture. 



A. F. Blakeslee 



THE PSYCHOLOGY OF SOCIAL CONSCIOUS- 

 NESS IMPLIED IN INSTRUCTION^ 



I HAVE been asked to present the social 

 situation in the school as the subject of a 

 possible scientific study and control. 



The same situation among primitive 

 people is scientifically studied by the 

 sociologist (folk-psychologist). He' notes 

 two methods in the process of primitive 

 education. The first is generally described 

 as that of play and imitation. The im- 

 pulses of the children find their expression 

 in play, and play describes the attitude of 

 the child's consciousness. Imitation de- 

 fines the form of unconscious social control 



' Read before Section L — Education. American 

 Association for the Advancement of Science, Bos- 

 ton, December, 1909. 



