ANALYSIS OP THE LESSONS. Xlli 



288. Description continued. 289. Differences in the mode of arrangement, and 

 consequent division of plants : character of Endogens. 290. Character of 

 Exogens. 291. And of Acrogens. 292. Resume. 293. Other distinctions. 294. 

 Recapitulation. 295. Exogens most numerous. 296. The Acrogen described. 

 297. Tree Ferns, the best example. 298. Transverse section of Tree Fern de- 

 scribed. 



LESSON XVIII. THE ENDOGENOUS STEM, p. 61. 



299. Its characters defined. 300. Endogens belong to hot climates. 301. 

 The Endogenous stem exemplified. 302. The early condition of it. 303. The 

 cellular tissue. 304. The dotted vessels. 305. Exempt from parasitic plants. 

 306. The soft wood is internal. 307. The rapidity of their growth. 308. Vas- 

 cular bundles of the Bamboo. 



LESSON XIX. THE EXOGENOUS STEM, p. 52. 



309. Originally cellular. 310. Development of other tissues. 311. Com- 

 pleted structure. 312. The second year's growth. 313. The Cambium cells. 

 314. The medullary sheath. 315. The second year's growth more fully ex- 

 plained. 316.- Changes in the permanent woody stem. 317. Order in which 

 the tissues are produced. 318. Tissues of the second year. 319. The third 

 year's growth. 320. The subject continued. 321. The characters of the tissues 

 given separately. The Wood. 322. How the layers of wood are formed. 323. 

 They consist of woody fibres. 324. Hardness of the wood in old trees. 325. 

 The heart-wood is colored in some trees. 326. Proportions of heart-wood and 

 albumen differ. 327. Durability of wood. 



LESSON XX. THE REMAINING TISSUES, . : . ;'.'' .' V;. : r v -. . . p. 55. 



The Medullary rays. 328. Their structure. 329. Their position. 330. Their 

 size varies. The Cambium layer. 331. Where situated. 332. Its composition. 

 333. What can be done in the spring. The Bark. 334. Its development. 335. 

 The inner bark. 336. The fibres of Bass-wood. 337. Separation of the fibres. 

 338. Immunity from decay of woody fibre. 339. The importance of woody 

 fibre : known to the ancient Egyptians. 340. They employed it in the manu- 

 facture of linen. 341. An ancient mummy exhumed by Belzoni. 342. A still 

 older one at Rome. 343. These facts known to microscopists. 344. Ancient 

 Peruvian mummy cloth. 345. Economic value of woody fibre. 346. Our obli- 

 gations to this tissue. 



PART II. 



ANIMAL TISSUES. 



LESSON XXL THE ORIGINAL COMPOUNDS OP THE ANIMAL BODY, . . p. 59. 



347. Composition and uses of the parts of an Egg. 348. Albumen : what 



becomes of it. 349. Its changes not confined to embryonic, or young condition 



of life. 350, Gelatine : what becomes of it. 351. Non-gelatinous tissues. 



