4 PLANT GROWTH 



and fruit. We cannot enumerate the many uses we find for 

 these manufactured products of the plant. We must, how- 

 ever, bear in mind that as in any factory a balance is main- 

 tained between the supply of raw material and the finished 

 products. 



Hybridizing of plants is becoming so important and so 

 popular that two extensive chapters are included to give a 

 scientific background and a working knowledge of the com- 

 mon methods. Of course the factual information covered in 

 many other parts of the book is fundamental to the study of 

 hybridizing. For example, the sections on chromosomes, 

 flower structure, and seed development should be carefully 

 studied before attempting any such plant improvement. 



Only a small portion of all the important and necessary 

 knowledge for the reader who wants to know all about plant 

 growth can be included in a single volume. It is hoped that 

 with the illustrations and text diagrams and with suggestions 

 about plants familiar to many people this may become useful 

 as a work book, with help from the addition of selected refer- 

 ences at the end of most of the chapters. The author has 

 attempted to list representative titles, but realizes that many 

 other equally important ones might have been added. Refer- 

 ences of a general nature, such as the various textbooks of 

 botany, review articles in special fields and research articles 

 in small parts of special fields are included from which the 

 reader will be able to select the ones best suited to his needs. 



Many of the illustrations were selected to show more 

 detail than described in this book, in order that they might 

 serve as an aid in terminology in more intensive reading. 

 The illustrations should be found valuable aids in helping 

 the reader to build a clearer mental picture of plant struc- 

 ture. The work of the plant can be understood and enjoyed 

 only as it is considered in relation to structure. 



Finally, in order to give further aid in the study of the 

 growing plant, a glossary of difficult terms has been included. 



