CONTENTS x i 



l'AUlii 



B. Translocation of Plastic Materials 327 



1. Conducting Parenchyma - - - - - -328 



2. Leptome -parenchyma (Cambiform Cells) - - - 328 



3. Sieve-tubes and Companion -cells .... 329 



4. Latex -tubes or Latieiferpus Elements - - - 336 



III. The Structure of Vascular Bundles .... :;n; 



A. Simple Conducting Strands - - - - - - 346 



B. Composite Conducting Strands 347 



1. General Considerations ...... 347 



2. Various Types of Composite Conducting Strand 349 



3. The Physiological Significance of the Different Types 



of Vascular Bundle ------ 353 



G. The Peripheral Bundle-ends ...... 365 



1). The Endodermis - - - - - - - - 368 



IV. The Arrangement and Course of Vascular Bundles - 374 



A. Course of the Vascular Bundles in Leafy Stems - - - 375 



B. Course of the Vascidar Bundles in Roots .... 385 



C. Course of the Vascular Bundles in Leaves - 386 

 V. The Conducting System in the Thallophyta - - - 389 



VI. Ontogeny of the Conducting System - 391 



CHAPTER VIII. 

 THE STORAGE SYSTEM. 



I. General Considerations 395 



II. The Storage of Water 397 



A. Water-tissues 397 



B. Mucilaginous Water-storing Cells ----- 403 



C. Water-storing Tracheides ------- 406 



D. Storage of Water in Intercellular Spaces - - - - 409 



III. Storage of Plastic Substances - - 409 



A. The Various Classes of Reserve-materials - - 409 



B. Storage-tissues - - - - - - - 418 



1. Tissues serving for the Storage of Plastic Materials 



proper ......-- 418 



2. The Storage of Respiratory Material - - - 426 



3. Storage for Ecological Purposes - - 428 



IV. The Storage -system in the Thallophyta - 430 



