1909] Bitter: Halocynthia johnsoni u. sp. 87 



ians, would almost certainly yield rich returns. But — and here 

 is the cardinal point — the exact nature of these various meristic 

 rules whose wide existence is revealed to simple inspection, can 

 be found only by the mosl exacting measurements and the most 

 rigid mathematical treatment of the data obtained by such meas- 

 urements. 



For the rest certain acknowledgments beyond the confines 

 of ascidian literature are due. These I make with heartiness 

 and pleasure, and regret that space limitations prevent partic- 

 ular mention of all but a few of the must pressing. 



My indebtedness to Bateson for his expansive conception of 

 merism has perhaps been sufficiently referred to already. 



Professor Minot has. in my opinion, opened the door more 

 widely than any other biologist to that vastly important subject, 

 the diminution in multiplicative and incremental activity within 

 the same organic system. Although I believe he will go astray 

 if certain of the interpretations contained in his discussions 

 mi eytomorphosis are followed up consistently, his data-collecting 

 and much of his presentation I regard as most admirable and of 

 far-reaching import. (See particularly Minot '91 and '08.) 



The well known work of Maupas ('83 and '89) and that by 

 Calkins ('9-4) of more recent date, on the running-down phe- 

 nomena in protozoan multiplication, bear almost, though not 

 quite as weightily in the same direction. 



Richard Hertwig's recent studies on nuclear and cytoplasmic 

 proportion in cells belonging to the same line of descent, though 

 carried on with the primary aim of gaining- light on the prob- 

 lem 'it' conjugation and sex are. it seems to me, of as much if not 

 more significance \'<>r the problem of meristic organization and 

 multiplicative activity. (Hertwig, '06.) 



Finally in Dr. Raymond Pearl's conception of "infra-individ- 

 ual variation," and the "laws of growth," presented especially 

 in his Geratophyllum paper (Pearl '07) we have, I believe, the 

 master stroke up to this time on the mathematical treatment of 

 organic development. Although as to the mathematical sound- 

 ness of such a work I am unfortunately utterly incompetent t i 

 speak, its general biological purport and sweep are unmistakabh 



