viii Contents. 



25. Influence of ether upon seeds 34 



26. Influence of sodium chloride upon germination 35 



27. Influence of copper sulphate upon germination 35 



28. Epinasty and hyponasty ....... 36 



29. Correlations .......... 36 



30. Formation of new tissues in healing wounds 37 



III. REPRODUCTION AND GERMINATION. 



31. Nature of reproduction and germination .... 38 



32. Germination of spores ........ 39 



33. Germination of pollen cells ....... 40 



34. Germination of grains of corn ...... 40 



35. Germination of seeds of Ricinus . . . . . .41 



36. Germination of peas ........ 42 



37. Germination and propagation of the tomato .... 43 



38. Germination of the seeds of the squash . . . .43 



39. Germination and propagation of Begonia .... 44 



40. Germination of seeds of Peltandra Virginica ... 44 



41. Sprouting of sweet potatoes ....... 45 



42. Propagation by various organs ...... 46 



IV. EXCHANGE AND MOVEMENTS OF GASES AND LIQUIDS. 



43. General physical nature of the plant 47 



44. Osmose .......... 49 



45. Osmose in plant tissues ....... 50 



46. Structure of an absorbing root 51 



47. Plasmolysis ......... 52 



48. Turgidity in an osmometer ....... 53 



49. Tissue tensions ......... 54 



50. Wilting 55 



51. Bleeding 57 



52. Amount of liquid exuded in bleeding ..... 58 



53. Measurement of exudation pressure ..... 58 



54. Imbibition pressure ........ 62 



55. Hygroscopic movements ....... 63 



56. Amount of stretching produced by imbibition and turgidity . 64 



57. Structure of a leaf of a mesophytic plant .... 65 



58. Structure of a xerophytic leaf ...... 65 



