760 



SCIENCE. 



[N. S. Vol. rv. No. 99. 



if they are not true dicotyledons, will prove to 

 be their immediate ancestors. But I certainly 

 do not believe that any number of well devel- 

 oped dicotyledonous plants will ever be found 

 in the Jurassic, nor that such plants flourished 

 at a period so remote. 



Aside from the Carboniferous and the Miocene 

 scarcely any geological age is better known 

 from the botanical side than the Jurassic. 

 From the Ehetic to the Wealden, rich Jurassic 

 floras have been made known in many countries 

 of Europe, in the arctic regions, in Siberia, in 

 China and Japan, in India, Australia, South 

 Africa and South America, and only last year 

 the discovery was made for, the first time, of a 

 true Jurassic flora in the United States, viz., 

 near Oroville, in California.* Yet of all the 

 hundreds of Jurassic forms thus brought to light 

 not one is dicotyledonous. 



In view of all this it is clear that there is 

 no room for controversy over the age of the 

 clays of Block Island or any of their equiva- 

 lents. When the vertebrate remains that Prof 

 Marsh has found in these beds shall have been 

 described, it will simply be a question of the rela- 

 tive weight that each one may choose to give to 

 the two classes of paleontological evidence be- 

 fore the world. Many of the plants have al- 

 ready been published with full drawings and 

 descriptions, and a list of them, which has since 

 been considerably increased, is given in my 

 paper on the Potomac Formation. Dr. New- 

 berry's work on the ' Flora of the Amboy 

 Clays ' will soon appear as a Monograph of the 

 United States Geological Survey, and Dr. Hol- 

 lick is now engaged on a similar monograph of 

 the flora of the Island Series. Those who are 

 capable of supposing that such a flora as this 

 could have flourished in Jurassic time are cer- 

 tainly at liberty to do so, and the geological 

 world will doubtless duly appreciate their cour- 

 age. Lester F. Ward. 



Washington, D. C. 



the date of publication. 

 In Science for November 6th Dr. J. A. Allen 

 objects to the resolution adopted by the Zoologi- 

 cal Section of the American Association 



*See Prof. Fontaine's paper in the Am, Journ. ScL, 

 for October, 1896, pp. 273-275. 



for the Advancement of Science at the Spring- 

 field meeting (1895), which recommended 

 that the date of printing be regarded as the 

 date of publication. He regards the posi- 

 tion taken in the resolution as expressiiag 

 both 'absurdity and mischievousness,' and in- 

 sists that sale, or distribution only, constitute 

 publication. He thinks that his opinion to this 

 eflect is a corollary of the definition given by 

 the Century Dictionary, namely, that publica- 

 tion consists of 'the act of oflering a book, 

 map, piece of music, or the like, to the public by 

 sale or by gratuitous distribution.' 



The resolution was presented to the Section 

 by a committee after consultation with many of 

 the members who are engaged in scientific pub- 

 lications, and who are perfectly familiar with 

 the subject in all its aspects. It was felt that, 

 while it would be very desirable if a rule of 

 distribution could be formulated, such a course 

 is simply impracticable. The difficulty of so 

 doing is set forth in the whereases that precede 

 the resolution. Dr. Allen has not met these 

 difficulties, but he adduces some objections to 

 the adoption of the date of printing as that of 

 publication. On the general position taken by 

 Dr. Allen I make the following comments : 



Fir^t. The date of printing, or alleged print- 

 ing, of the last printed part of a book, the title 

 page, has always been regarded as the date of 

 publication. Who has ever inquired into or de- 

 termined the date of sale or distribution of any 

 scientific book published during the past, up to 

 within a very few years ? We are accustomed 

 to refer to the title page, or last page, to ascer- 

 tain this date, for further than that we cannot 

 go. In most instances it will be impossible to 

 ascertain the date of sale or distribution of 

 books published in past years, apart from the 

 date of printing. 



Second. The probabilities are so great that a 

 book is ' offered to the public ' at the date af- 

 fixed to it, that it is not safe to assume that it is 

 not, except in two contingencies. The first is 

 the case of fraudulent antedating of a book. 

 This is likely to be of extreme rarity among 

 scientific men, and if attempted would be easily 

 detected by reference to the records of the print- 

 ing office. The second case is the one brought 

 forward by Dr. Allen, that of government pub- 



