No. 559] 



NOTES AND LITERATURE 



431) 



air is practically a negligible factor in seeding infusions (19. pa-e 2(53 L 

 The order in which different common forms most frequently 

 appear, reach their maximum, and disappear in hay infusions is 

 shown in the following list (taken from 19, page 243). 



Appearance 

 Monads. 

 Colpoda. 

 Hypotriehida, 



Maximum 



1. Monads. 



2. Colpoda. 



3. Hypotrichida. 



4. Paramecium. 



5. Amoeba. 



Disappearance 



1. Monads. 



2. Colpoda. 



3. Hypotrichida. 



4. Amoeba. 



5. Paramecium. 



6. Vorticella. 



As hay infusion is the typical culture medium for such organ- 

 isms, a study was made by Fine (20) of its chemical properties, 

 with particular relation to the acidity, the purpose being to 

 correlate, so far as possible, the chemical conditions with the 

 protozoan sequence. The paper concludes : 



The aei 



The 



of ] 



play a relatively 



possess no intimately mutual relation. Either mav vary 

 limits without appreciably influencing the course of the othe 



This line of work is evidently still under active 

 since we note that the Journal of Expt ri»\( >\t<tl Zoology prom- 

 ises a paper by Woodruff on "The Effect of Excretion Products 

 of Infusoria on the Same and on Different Species, with Special 

 Reference to the Protozoan Sequence in Infusions." 



The problems of reproduction, age and death are bound up in 

 recent theories with those of the size of cells and nuclei ; a paper 

 on this aspect of matter in the same journal is likewise promised 

 from Woodruff. 



Among the laboratories of this country which have made a 

 definite mark on some unified problem of general interest (and 

 such are happily now becoming numerous), certainly a most 

 honorable place must be accorded to this work done at Yale by 

 Woodruff and his associates. 



A. R. Middleton 

 Zoological Laboratory of the Johns Hopkins University 



