119 



table showing the total surface of the 2,000,000 feet of roots and 

 6,000 miles of root hairs of a single grass. There are many such 

 tables. 



The development of physiology has been at the expense of 

 taxonomy, morphology, and even genetics. Chapter III, "Learning 

 How to Name Plants," really is concerned with the terminology 

 of leaves, and contains scant reference to the naming of plants. 

 There is nowhere in the book any attempt to present a scheme of 

 classification of the plant world or to explain the principles on which 

 such a scheme might be based. The comparative morphology of the 

 various groups, i.e., what used to be called a survey of the plant 

 kingdom, occupies only about a fifth of the book, and the descrip- 

 tions of the so-called lower groups are scamped to a degree which 

 will disappoint many teachers and even some students. A book 

 of this size might be expected at least to serve as a reference work for 

 a certain amount of morphological detail. In short, while the re- 

 viewer has long advocated a trend in this direction, he feels that 

 this book has over-shot the mark. The treatment of genetics seems 

 at the same time over-simplified and involved. Meiosis is repre- 

 sented as involving merely the pairing and disjunction of homolo- 

 gous chromosomes ("the chromosomes do not 'split' "). Crossing- 

 over is mentioned only incidentally in the following confused state- 

 ment: "A third type of irregularity has been variously called 

 'translocation,' 'segmental interchange,' and 'crossing-over.' " 



The wider the scope of a general text, the more certainly will 

 there be errors. In this book a few are evident. Perhaps the worst 

 is the statement on page 402 that "embryos develop from vegetative 

 cells in the notches of the leaves of bryophyllum." On page 55 a 

 distinction should be made between light (which does not increase 

 the rate of evaporation) and the heat due to absorption of light 

 (which does). On page 202 we are led to believe that the solution 

 of sugar in water will always cause an increase in volume of the 

 liquid. On page 527 Franz Schulze is referred to as "Schultze." 

 On page 582 PlasniodiopJiora Brassicae is described as "a simple 

 mold." Inflorescences, so commonly confused by modern botanists, 

 are more than usually so on pages 360 and 361, where an attempt is 

 made to classify them without reference to the order of flowering, 

 and the milkweed acquires an umbel in consequence. Figure 45 

 is wrongly oriented. 



