jan. 3 ,1916 Effect of Low Temperature on Fungi and Bacteria 655 
If the results of the exposures of these organisms to low temperature 
are summarized, it will be noted that five fungi, Sclerotinia cinerea, 
Cephalothecium roseum, Glomerella rufomaculans , Venturia inequalis f 
and Ascochyta colorata, lived over winter under all conditions of expo¬ 
sure; while four others, Alternaria solani , Cylindrosporium pomi, Plow - 
rightia morbosa , and Phytophthora omnivora, lived over on some media 
but not on others. One fungus, Fusarium sp. of conifers, succumbed 
to the low temperature, while two others, Colletotrichum Lindemuthianum 
and Sphaeropsis malorum, were so weak that only under very favor¬ 
able conditions would they respond to fresh media. Only two of the 
six kinds of bacteria exposed can be safely said to have survived— 
Bacillus melonis and Actinomyces chromogenus . Transfers from ex¬ 
posed cultures of B . melonis were found to agree in all distinctive 
characters with those given by Giddings. It is to be noted that this 
organism forms no spores. The growth of transfers from exposed 
cultures of Actinomyces chromogenus was very characteristic and hardly 
mistakable for any other organism. In regard to the other bacterial 
cultures, it may be said that they were more or less contaminated during 
the exposure; and although some of the transfers from them resemble 
the original growth, this was not well enough marked to prevent all 
suspicion. On the whole, the various organisms seem to withstand 
exposure better in a dry condition than when food and moisture are 
present. 
Thinking that some of the organisms might die from natural causes 
other than the exposure to low temperature, the author retained part 
of the culture made for this test indoors as a check. They were kept 
in a cool room (14 to 20° C.) throughout the winter and tested for vitality 
late in March, 1914. In practically every case these cultures were 
living at that time, and no organism given in Table III can be said 
to have died otherwise than by exposure to low temperature. 
No entirely satisfactory explanation has been offered as yet of the 
changes which take place in fungi and bacteria during or after exposure 
to extreme cold. The results obtained by the author throw little or 
no light on the manner of the freezing nor on the subsequent death. 
The present work is a record of the fact that certain fungi and bacteria 
are able to withstand extreme cold, while others succumb to it, but 
does not attempt to advance any theory as to the internal changes 
which contribute to the weakening or death of the organisms thus tested. 
