No. 525] SHORTER ARTICLES AND DISCUSSION 



Some series of cultures which produce no oogonia are believed 

 by the author to possess ;i distinct physiological cliaracter in this 

 respect, whereby they can be readily separated from series which 

 produce oogonia. If these organisms obey the same general laws 

 as those with which we have been working, it would be injudici- 

 ous, at least, to say positively that they do not produce oogonia 

 without having grown them for many generations and from dif- 

 ferent individuals of the same origin. 



The idea, that the same conditions of nutrition, temperature 

 and general environment always produce the same results upon 

 the individuals of a species of organism, has, we believe, as yet 

 no sufficient basis in demonstrated fact. The suggestion of the 

 author, that a standard for the measurement of species compar- 

 able to the standards used in physics and chemistry, can be de- 

 vised, is, we fear, a delusion and indicates a failure to 



sess inherent tendencies or forces which may enable them 

 without necessary dependence on any particular nutritive 

 stance or environmental condition which can be at present 

 definitely determined. The causes of these variations or muta- 

 tions may perhaps be determined when we are able to recognize, 

 analyze, measure and control all the numerous delicate complex 

 factors concerned, many of which are now probably bevond us 

 and not even surmised. 



At another point essentially the same solution of the ever- 

 vexing and recurring species question is given as follows: "At 

 first thought this seems to indicate that no separation can be 

 made of the different species of Saprolegniacea? by means of con- 

 stant characters. We can, however, use the resources of the 

 chemist and physicist, and, by stating the exact conditions of 

 culture establish a standard to which all forms may be referred." 

 It is further stated: "It would seem necessary, then, in mono- 

 graphing such a family as the Saprolegniacese to refer all the 

 species to definite conditions, which should be uniform for all, 

 and to determine in each case the variability to the extreme at- 



