56 PROTECTIO>^ OF PLANTS, 1920-21 



The viable spores germinated in two days and only in rare instances did 

 any germinate after two days in the hanging drop. 



Spores taken from a plant which had been frozen seven days, kept at room 

 temperature four days, then frozen again for four weeks gave only a slight ger- 

 mination (2%). 



The promycelia varied in length from one to four times the length of the 

 spores. The sporidia were hyaline, spherical to obovate, smooth, varying in 

 diameter from 4 — 9 microns. 



A record of the meteorological observations for the month of January was 

 obtained from McGill University in order to have accurate data of the temper- 

 ature for the period January 4th to 18th inclusive. 



Days.. Mean. Max.. Min.. Range.. 



January 4.. 32..9 36..8 29 7..8 



5.. 29.0 32.2 23.7 8..5 



6.. 17..6 23..7 11.8 1L.9 



7.. 14.8 23..5 6.0 17-.5 



8.. 24..0 27..0 21.0 6..0 



9.. 22..5 28..0 19..8 8..2 



10.. 25..8 32..8 19.9 12..9 



11- 25.6 31..5 21.8 9-7 



12.. 13.8 18.0 6..0 12..0 



13.. 3.5 10.-0 -4 3 14.3 



14.. 17..3 27.0 6 3 20..7 



15.. 28.1 31..0 20.0 11.0 



16.. 8..5 19..0 ..5 18.5 



17.. 6.7 19.4 -7..5 26.9 



18.. -9..8 -6.8 -14..2 7.-4 



From this record we are able to obtain the lowest and highest temperatures 

 to which the spores were subjected in the different trials. Those that were 

 frozen for one day (January 4-5) were under weather conditions ranging from 

 36.8 to 23.7, with a mean temperature of 30.6. The spores subjected to outdoor 

 conditions from January 4-11 suffered a range of temperature from 36.8 to 6,0, 

 with a maximum range on January 8th of 17.5. The mean temperature for 

 these seven days was 24.0. The spores that were left outside until January 

 18th underwent a range in temperature of 51.0 in the two weeks, with the lowest 

 mark — 14.2 on the day they were brought indoors. The mean temperature 

 for the two weeks was 18.6. All temperatures are in Fahrenheit Degrees. 



Experiments in Inoculation 



Seedling plants of A. Majus were inoculated with (a) germinating tehospo- 

 res bearing sporidia, (b) teliospores from plants which had been frozen two weeks 



