vi CONTENTS. 
CHAPTER ITI. 
AGGREGATION OF THE PROTOPLASM WITHIN THE CELLS OF THE 
TENTAOLES. 
Nature of the contents of the cells before aggregation — Various 
causes which excite aggregation — The process commences 
within the glands and travels down the tentacles — Descrip- 
tion of the aggregated masses and of their spontaneous 
movements — Currents of protoplasm along the walls of the 
cells — Action of carbonate of ammonia — The granules in 
the protoplasm which flows along the walls coalesce with the 
central masses — Minuteness of the quantity of carbonate of 
ammonia causing aggregation — Action of other salts of 
ammonia — Of other substances, organic fluids, &c—Of 
water — Of heat — Redissolution of the aggregated masses — 
Proximate causes of the aggregation of the protoplasm — 
Summary and concluding remarks — Supplementary observa- 
tions on aggregation in the roots of plants .. Pages 38-65 
CHAPTER IV. 
Tae Errrots oF Heat on THE LEAVES. 
Nature of the experiments — Effects of boiling water — Warm 
water causes rapid inflection — Water at a higher tempera- 
ture does not cause immediate inflection, but does not kill 
the leaves, as shown by their subsequent re-expansion and 
by the aggregation of the protoplasm — A still higher 
temperature kills the leaves and coagilates the albuminous 
contents of the glands.. .. «2 «0. on owe) 66-75 
CHAPTER V. 
Tut Errects or NoN-NITROGENOUS AND NITROGENOUS 
Oreanic FiLvips on THE LEAVES. 
Non-nitrogenous fluids — Solutions of gum arabic — Sugar — 
Starch — Diluted alcohol—Olive oil—Infusion and decoc- 
tion of tea — Nitrogenous fluids — Milk — Urine — Liquid 
albumen — Infusion of raw meat— Impure mucus — Saliva 
—Solution of isinglass — Difference in the action of these 
two sets of fluids — Decoction of green peas — Decoction 
and infusion of cabbage — Decoction of grass leaves 76-84 
