Notes and Comment. 



297 



from the others mentioned. The second division presents an 

 interesting discussion of stimulation from souiccs internal to 

 the plant as a whole. Here the main topics aie treated : 1 . The 

 various correlative phenomena of growth or depression following 

 feitilization. 2. The transference, through changes in internal 

 condition, of a tropic state from one organ to another, for ex- 

 ample, the relation maintained between the segments of jointed 

 plants, such correlations as between a flower oi fruit and its 

 *stalk, where the tropic conditions of the latter varies with the 

 morphological stage of the former, or the regulatory influence 

 of the main axis on the nature of the lateral organs. 3. The 

 libeiation of formative stimuli. Here are discussed polarity, 

 ceitain types of regeneration, etc. 4. Correlation of growth. 

 5. Correlation between paits of the cell. In the closing chapter 

 the author argues for a much more extensive action of the 

 phenomena of iiritability than is generally held. He considers, 

 for example, many of the internal correlations of growth and 

 organization to be fundamentally phenomena of irritability 

 rather than of nutrition. 



The second part of the book deals with the process of irri- 

 tation through the plant and this is treated under the following 

 heads: 1. The paths along which stimuli are transmitted. 

 2. Distance and rate of transmission. 3. Dependence upon ex- 

 ternal conditions. 4. Difference in electrical potential accom- 

 panying the transmission of some stimuli. 5. The natuie of the 

 process of the transmission of stimuli. 6. The relation of the 

 actual conduction of the stimulus to the other parts of the pro- 

 cess, i. e. to the perception and reaction phenomena. The b6ok 

 includes a very complete literatuie, and, unfortunately, lacks 

 an index. 



NOTES AND COMMENT. 



The guide to the newly established garden of Johns Hopkins 

 University, recently reprinted fiom a University calendar, 

 indicates on the part of those in charge a clear conception of what 

 a garden planned primarily as an aid to botanical research and 

 instruction should be. As stated in the introductory pages of 



