'r III ixniosnnifi Iciris'i was round alls'c aflcr iimnci'siou 

 of the ciillurc in liquid aii" lor 7") minnU's, 1ml it was killed 

 after 24 hours (aceordiiii;' to Dollein's "Leln-bncli dcr 

 Pi-otozoeiikiuide," 3rd ed., ]). 230, Jena, 11)11). 



De Joiii;' (1922) reporled llie results obtained in liis 

 lal)ora1()ry l)y Zaiidberi>eii (11)22) on Trypanosoiua as 

 follows : Tri/jjaiiosoma Icwisi was killed at -20° in 8 

 minutes, at -30° in one hour and at -190° in 2 hours; 

 Trypanosoiua equiperdum lost its motility and pathoge- 

 nieity by a stay of 3] hours at -20°; at -39°, -65° and 

 -145° it lost its motility but not its pathogenicity; at 

 -191° it was still motile and pathogenic after 21 days. 

 Trypanosoma venezuelense and bnicei behaved in the 

 same manner at T. equiperdum. 



Becqiierel (1936) found living Eugleua viridls in dried 

 soil subjected to liquid helium in a high vacuum. 



A general survey of the monocellulars reveals that : 

 1. Most of the bacteria, bacterioids, yeasts, algae of the 

 type ChJorcUa or Stichococcus and flagellates of the type 

 Trypanosoma, in the vegetative state and in their aqueous 

 culture medium, are not destroyed by the lowest available 

 temperatures acting for some hours ; 2, When the bacteria 

 and bacterioids are affected by the temperatures of the 

 liquid gases, the influence of the factors: species, time of 

 exposure, concentration of the medium, and repeated con- 

 gelation has been emphasized but is not clear; 3. The 

 rhizopods, ciliates, and flagellates of the type Eugleua, in 

 the vegetative state, and in an aqueous medium, do not 

 resist more than a few degrees below zero and are usually 

 found dead after they had been congealed; 4. All the 

 monocellulars resist temperatures near the absolute zero 

 in the encysted and dry state. 



III. GERM CELLS, SPORES AND SEEDS 



1. Spermatozoa. Our knowledge of the resistance of 

 spermatozoa to cold is gleaned mostly from scattered data 

 obtained as secondary results in the study of other prob- 



