62 



DOMESTIC BOTANT. 



sidered spherical, but by equal pressure on one another 

 the section represents a hexagon, which however as- 

 sumes various forms in different plants. These are the 

 elementary organs or simplest condition of vegetable 

 structure, and known as cellular tissue. Vascular tissue 

 consists of membranous tubes of various kinds, lying 

 embedded in a vertical direction in the cellular tissue. 

 They either taper to each end, or terminate abruptly ; 

 some enclosing a closely coiled spiral thread, called spiral 

 vessels (fig. 9, h), which may readily be seen on gently 

 tearing asunder the stalk of many plants, such as rhu- 

 barb, the young shoots of elder, footstalks of strawberry 

 leaves, and many bulbs. Ducts are other kinds of tubes, 

 transversely marked with rings or bars, but do not un- 

 coil. Woody tissue, or fibre, consists of slender tubes 

 in bundles, narrowing at both ends. In the Fir family 

 it is perforated with pores called glandular tissue. Many 

 other curious forms of vessels are found in plants, all 

 affording great scope for microscopic investigation^ 

 of the nature of which, and the part they act in the life 

 of a plant, there are various opinions. Knowing that 

 such is the plan of construction, the microscope is not at 

 first necessary to the amateur student for his practical 

 study of outer forms. 



Erom what has been stated above, it will be seen that 

 the structure of plants consists of simple cells only, or of 

 cells and tubular vessels combined ; the first compre- 

 hends cellular plants; or Cryptogams (flowerless), con- 

 sisting of the whole of the plants in the twenty-fourth 

 class of Linnseus — viz., mosses, ferns, lichens, algae, 

 and fungi. These are the lowest types of vegetable 

 life, having no visible stamens, pistil, or true seed, 

 their reproduction being by what is called spores. 



