Sept. 1907] Cultures of Uredineae in igo6 191 



were made to test the germinating condition of the spores. Out 

 of the 94 collections with resting spores 46 could not be made 

 to germinate, although no reason could be assigned why they 

 should not. This gave 48 collections of available material be- 

 longing to 30 species of rusts, exclusive of the aecial pine rusts, 

 and from these 223 sowings were made. Beside these 53 sowings 

 were made with Caeoma and Peridermium spores from pine, 

 all without infection, 27 sowings with teliospores of Gymno- 

 sporangium, and 23 sowings with various aeciospores. Alto- 

 gether 326 sowings were made, and for this purpose 134 species 

 of hosts were required, which were grown temporarily in the 

 greenhouse, where practically all the work was done. The re- 

 sults of this work are given in the following paragraphs, and 

 are divided into negative results, positive results with species 

 whose life histories have already been previously determined, and 

 positive results with species whose life histories have not before 

 been fully known. 



Of the trials giving negative results the following may be 

 recorded to serve for reference in further studies. 



1. PucciNiA on Car ex P ennsylvanica Lam., collected near 



Lafayette, Ind., was sown on Trillium reciirvatum, Napaea dioica, 

 AnemoneUa thalictroides, Isopyrum hiternatum, Anemone vir- 

 giniana, Actaea alba, Viola cucullata, Dirca pahistris, Polemonium 

 reptans. Ambrosia triUda, Riidbeckia laciniata, and Lactiica cana- 

 densis, with no infection. Similar material in former seasons 

 has been tried on eighteen other species of hosts with negative 

 results.^ 



2. PucciNiA on Carex gravida Bailey, sent by Rev. J. M. 

 Bates from Red Cloud, Neb., was sown on Actaea rubra, Thalic- 

 trum dioicum, Isopyrum biternatum, Apios Apios, Falcata comosa, 

 Psoralea Onobrychis, Cassia Chamaecrista, Polygala Senega, 

 Aesculns glabra, Ceanothus americanus, Smilax herbacea, Viola 

 cucullata, Napaea dioica, Callirrhoe involucrata. Althaea rosea. 

 Hibiscus Moschcutos, Macrocalyx Nyctelea, Polemonium reptans, 

 Myosotis pahistris. Phlox divaricata, Phlox subidata, Triosteum 

 perfoliatjim, Boltonia asteroides, Laciniaria pycnostachya, Rud- 

 beckia laciniata, Senecio obovatus, and Cacalia reniformis, with 

 no infection. Similar material from the same source has been 

 sown in previous years upon eleven other species of hosts with 

 negative results.* 



3. PucciNiA on Polygonum scandens L., obtained in the 

 vicinity of Lafayette, Ind., was sown five times on Geranium 

 maculatum, twice on G. Robertianum, twice on G. pusillum, and 



'See Jour. Myc. wAO. 1904; /j:o1. 1905; and 12 :12. 1906. 

 *See Jour. Myc. /o:10. 1904; and 7J:52. 1905. 



