244 Proceedings of Indiana Academy of Science 



hand, teliospores of a species which usually gives germination the fall 

 of the year in which they mature also may germinate the following 

 spring. In such a rust, Puccinia disj)ersa, twelve collections showed 

 teliospores germinable between Aug. 19 and Nov. 25, 1919. Two addi- 

 tional collections gave germination in December. Of these 14 collec- 

 tions, five still gave germination the following spring on April 7, 1920. 

 3. Methods of Testing the Germination of Spores. It is evident 

 that, before inoculating with teliospores, it is of considerable importance 

 to know whether they are germinable. In the case of aeciospores and 

 urediniospores it is not so essential as they usually can be relied on to 

 give some germination from fresh material. With old inoculum, or 

 where the plants to be inoculated are uncertain hosts, it is well to make 

 germination tests in order to give proper value to negative results. 



Fig. 1. Methods of testing spore germination. A. Petri dish; B. Syracuse watch 

 glasses ; C. ModifiGtl Van Tieghem cells. 



Several different methods of making spore germination tests have 

 been in use in this laboratory, being more or less modifications of those 

 used by a number of other investigators. Modified Van Tieghem cells 

 (fig. 1, C) were fir.st used. In this method a drop of water is placed 

 upon a cover glass and the spores are added to this drop. Water is 

 placed also in the bottom of the cell which consists of a glass ring 

 sealed onto a glass slide. The cover glass, with drop, is inverted and 

 sealed with vaseline to the upper side of the ring. 



A metal microscope-slide case was found very convenient in hand- 

 ling germination tests of 200 to 300 collections of teliospores, made about 

 once a week during the spring months. Every other tray was removed 

 and this gave plenty of room for the Van Tieghem cells, allowing them 

 to be stored in a small space. These cells make easily possible the ex- 

 amination of the spores with the 4 mm. objective of the microscope with- 

 out disturbing the humidity. Where frequent and numex'ous tests are 



