12 INTRODUCTION 



10. Tissue is a term used to denote any animal or vege- 

 table substance that is composed of a particular kind of 

 material and that performs a particular office or function. 

 Thus, for instance, we have bony tissue and muscular 

 tissue in animals ; that is, tissue made of bone substance 

 and of muscle substance and doing the work of bone and 

 muscle respectively. So in plants, we have woody tissue, 

 or tissue made of woody substance, and vascular tissue, or 

 tissue made up of little conducting vessels, which have 

 their especial functions to perform. 



11. Appliances needed for General Use. — The only appli- 

 ances necessary for the study of this book, besides the 

 material furnished by the ■ woods and fields about us, are 

 so few and simple that there can be no difficulty in pro- 

 viding them. The following list comprises about all that 

 are essential : — 



Half a dozen glass jars ; preserve jars or wide-mouthed 

 bottles will answer. 



Half a dozen soup plates or other shallow dishes for 

 germinators. 



Some good-sized bits of window glass for covering jars 

 and dishes. 



A garden trowel. 



A good hatchet for use when the study of timber is 

 taken up. 



A very sharp knife — a razor is better, if it can be 

 obtained — for making sections. 



A small whetstone for sharpening knives. 



A vial of tincture of iodine. 



A pint of red ink ; or, if preferred, a good coloring fluid 

 can be made by purchasing an ounce or two of eosin from 

 the druggist and mixing it with water. 



A pot of photograph paste. 



If a yard or two of India rubber tubing, a common bulb 

 thermometer, and a pair of druggist's scales are added to 

 the above list, the number of experiments that can be per- 

 formed will be considerably increased. 



