YOUNG GROWING TISSUES CONTAIN MUCH WATER. 15 



can perform at all wLen tlie person is out of health. 

 The tissues of the aged are dryer than those of the 

 adult, and the tissues of the infant are very soft and 

 succulent. The tissues lose water and become 

 firmer, tougher, and some of them more brittle as 

 age advances, and the rate of nutrition and growth 

 are modified accordingly . 



26. Young growing ti$>sues contain much water. — 

 The succulent tissues of the young grow fast, but 

 the dry textures of the aged shrink and waste 

 instead of growing. The rate at which a tissue 

 grows varies greatly at the different periods of life. 

 All the different tissues are formed at a very early 

 period of hfe — long before birth, at which time all 

 the tissues exist though in a verj soft and succulent 

 state, and are easily injured, owing to their delicacy 

 and want of firmness. This difference in the rate 

 of growth at different ages is due entirely to the more 

 ready access of pabulum at the early stage, as will be 

 more fully explained in another lecture. 



'i'Z. All organs come from bioplasm. — All the dis- 

 similar tissues of a man are represented by the soft 

 transparent bioplasm which is of the same consistence 

 throughout and possesses the same character in every 

 part. At the first the quantity of this bioplasm is 

 so very small that it can only be seen through a micro- 

 scope. It looks perfectly clear, and there is no indi- 

 cation of structure in any part. Yet the skin and 

 bones and muscles and all the other organs ulti- 

 mately come from it. It takes up food and increases. 

 Gradually certain portions begin to form one tissue, 

 and other portions another, and so on, tmtil indica- 

 tions of all the different textures are to be made out, 

 but being so soft and delicate their examination re- 

 quires the greatest care. 



28. Bioplasm in Iiealth and disease and at all ages. 

 — The bioplasm in all living things undergoes change. 

 The lifeless food we take becomes converted into bio- 



