284 



SCIENCE. 



[K S. Vol. XXIV. No. 609. 



which include a larger number of figures, 

 mostly life-size. The author's purpose has 

 been to give especial attention to the young 

 fern from the time its first leaves appear up 

 to the mature plant. These stages are illus- 

 trated by numerous figures, and these are sup- 

 plemented by popular descriptions. The book 

 will be very helpful to the class of people for 

 whom it is primarily designed, while at the 

 same time it will be useful to the scientific 

 botanist who will find here much exact in- 

 formation about young ferns that he can not 

 find elsewhere. 



Somewhat like the last is Laing and Black- 

 well's 'Plants of New Zealand' (Whitcombe), 

 which is designed ' to give an account of our 

 native plants that will be intelligible to all.' 

 It makes no attempt to notice or describe all 

 of the species, dealing only with the more 

 conspicuous flowering plants, and omitting 

 the grasses and sedges, in addition to ' certain 

 less important orders.' The introduction of 

 nearly sixty pages includes a general discus- 

 sion of the vegetation, in which the author 

 has packed a great deal of most interesting 

 information, although such words as ' forma- 

 tion,' ' zonation,' ' succession,' ' alternation,' 

 * f acies,' etc., are conspicuously absent. Nor 

 do we find that much-abused and long-suffer- 

 ing word ' ecology,' although the book is full 

 of what it is now the fashion to call by that 

 name. In short, this is an entertaining and 

 instructive account of tha plants of New 

 Zealand told by men who have sufficient mas- 

 tery of the English language to be able to 

 write with clearness and accuracy. The book 

 reminds us of ' Minnesota Plant Life,' written 

 by Professor MacMillan, also a master of 

 English, though by no means wanting in 

 ability to write most technically on occasion. 

 There is the same careful selection of ma- 

 terial, the clear treatment and wealth of 

 beautiful and apt illustrations. May we not 

 here express the hope that Messrs. Laing and 

 Blackwell may long continue to study and 

 write about the plants of their country, and 

 that New Zealand botany may not have to 

 suffer such a loss as that involved in the re- 

 tirement of Professor MacMillan from active 



botanical work in this country. Science can 

 not spare such men. 



A STUDY OF THE COCONUT TREE. 



In an interesting paper published in the 

 Philippine Journal of Science, Dr. E. B. 

 Copeland gives the preliminary results of 

 some studies of the coconut tree which he has 

 made, especially with reference to its water 

 relations. Incidentally a good many interest- 

 ing facts are brought out in the course of the 

 discussion. Thus even on large trees the roots 

 are only about a centimeter in diameter, and 

 they spring in great numbers (on large trees 

 as many as 8,000) from the convex or ob- 

 conical base of the trunk, which itself may 

 reach a depth of 50 centimeters. These 

 slender roots may be 5 to 7 meters long, and 

 are simple, or branched at right angles to the 

 root axis. They are very strong and elastic, 

 and attach themselves to the soil with such 

 firmness that the tree is never uprooted. The 

 stem may reach 80 centimeters in diameter, 

 and is so elastic as rarely to be broken even 

 in the fiercest storms, although the favorite 

 habitat of the tree is the seashore where it 

 receives the imbroken force of the tropical 

 .winds. 



Careful studies of the leaf were made, es- 

 pecially with reference to its loss of water 

 (transpiration). These show that older leaves 

 (one year old) lose more water than young 

 leaves which have just reached their full size. 

 This result agrees with observations made by 

 Bergen on the leaves of the myrtle (Myrtus) 

 in Italy. Some rough estimates were made 

 as to the total amount of water transpired 

 by the tree annually, which show that for an' 

 average tree it is more than 10;000 liters. 

 This is a remarkably large amount when we 

 consider the rather limited leaf area exposed 

 by the tree. Charles E. Bessey. 



The University of Nebeaska. 



DISPUTED VE8UVIAN ERUPTIONS. 



Nine eruptions of Vesuvius are commonly 

 admitted to have occurred during the first 

 twelve centuries of our era, the volcano after- 

 wards remaining quiescent until the parox- 

 ysmal outburst of 1631. Two minor disturb- 



