GYD GYD GYD CYD GYS GYD GYD 



4/CT^ ^v^ /CP^ t/v^t 4AP* *^r>* i/u^rf 

 **uv* '\jv' %^** *W* "yCW" *\y* **&*"* %0^* %^" 



> GAD CAT* GAD c3CD G3Cr> CIXD QAD CAD GAD 



APPENDIX A. 



r I ^HE subject of local circulations has been 

 JL so clearly handled by Professor Henslow, 

 and is in itself so important a physiological fact, 

 that no apology is necessary for transferring his 

 account of the matter to these pages, which is 

 here done in a somewhat abridged form. 



" In the ascent, descent, and general transfu- 

 sion of the sap, we can trace the operation of 

 physical causes modifying and controlling to a 

 considerable extent, if, indeed, they do not origi- 

 nate and entirely regulate those movements. 

 We have now to describe a more remarkable 

 movement of the juices of some plants, which 

 more decidedly evinces a vital action. This 

 movement consists in a constant rotation of the 

 fluid contained in their vesicles or tubes, and 

 rendered apparent by the presence of minute 

 globules of vegetable matter floating in it. The 

 original discovery of this phenomenon was made 

 about a century ago by Corti, who first observed 

 it in the Caulinia fmgilis, a maritime plant 

 found on the shores of Italy. His observations 



