July 21, 1911] 



SCIENCE 



95 



fungi might be influenced if not determined 

 by the acidity of the boards. 



In order to determine the relation of species 

 of Geratostomella to various quantities of 

 acids and alkalies in the medium upon which 

 they grow, a number of experiments were 

 made with definite additions of acids and 

 alkalies to a medium of known character. 



Laboratory Experiments. — A nutrient me- 

 dium of .5 per cent. Liebig's extract, 1 per 

 cent, malt extract and 2 per cent, agar agar 

 neutralized to phenolphthalein with NaOH 

 was prepared, to which .5, 1, 1.5 and 2 per 

 cent, sodium carbonate c.p. (NajCOj) and 

 .5, 1, 1.5 and 2 per cent, citric acid (C,HjOj + 

 HjO) were respectively added. To these 

 media and to the neutralized medium the 

 mycelium of actively growing Geratostomella 

 ecliinella E. & E. was transferred. There 

 was excellent growth on the acid and neutral 

 media, but none on that containing excess 

 sodium carbonate. The spores of G. echinella 

 germinated on the media containing .5 per 

 cent. ISTa^COj, but 1 per cent. ISTa^COj inhib- 

 ited growth. 



After this fresh sap boards of yellow pine 

 (Pinus palustris) and of red gum (Liquidam- 

 har styraciflua) were dipped in various solu- 

 tions of sodium carbonate and of sodium 

 bicarbonate. The boards were inoculated 

 with spores of Geratostomella echinella and 

 then stacked in compartments whose tempera- 

 ture averaged about 17° F. and whose atmos- 

 phere was so moist water collected in drops 

 on the sides of the compartments (optimum 

 conditions for blue stain). The result of the 

 experiment is tabulated below. Fungus in- 

 fection is indicated by -\-, sterility by 0. 

 The number of boards dipped in a solution 

 varied. There were always two at least. 



SAP YELLOW PINE 



Inoculated with Geratostomella spores 

 Dipped in boiling 

 BtO-t- 



1^ Na-COa + 1^ HNaCOa + 



3^ Na^COa + 3^ HNaCOs -|- 



5^ Na.COs + 5^ HNaCOa + 



7^ Na^COa 7^ HNaCOj 4- 



8^ Na^COj 8^ HNaCO, 



10^ Na^COa + slightly. 10^ HNaCOj -|- slightly. 



Dipped m eold solutions of: 

 6^ Na^GOs + 6^ HNaCOa -f 



8^ Na^GOa + 8^ HNaCOa + 



10^ Na^COa + 10;^ HNaCOa + 



H,0 + 



SAP EED GUM 



Inoculated with Ceratostomella spores 

 Dipped m. boiling 

 BL,0 + 

 If Na^COs + 1^ HNaCOa + 



Z% Na^COa -f 3^ HNaCOa -f 



5;^ Na^COa + 5i HNaCOa + 



. 7^ Na,COa + slightly. 7^ HNaCOa + 



8^ HNaCOa + slightly 

 10;^ HNaCOa -\- slightly. 



Dipped in cold solutions of: 

 3^ Na,COa + 3^ HNaCOa + 



5^ Na,COa + 5!l HNaCOa + 



7^ HNaCOa + 



SAP KED GUM 



Inoculated with Geratostomella spores 

 Dipped in 

 H,0 + 



All boards equally 

 infected. 



5^ aSOi + 



; H,80i + 



The cold soda solutions were found not to 

 be as effective as the hot solutions. This may 

 have been because the boiling solutions by re- 

 moving air bubbles came more in contact with 

 the wood fibers, and because they penetrate 

 the wood. According to the laboratory test 

 of the board-dipping process, 7 and 8 per cent, 

 solutions of sodium carbonate and 8 and 10 

 per cent, of sodium bicarbonate gave the best 

 results. Spores germinated on these boards, 

 but the mycelium did not grow so that it 

 could be seen by the naked eye. 



To summarize the results of the laboratory 

 experiments : 



Geratostomella echinella spores germinated 

 on a nutrient agar medium which had been 

 neutralized to phenolphthalein with sodium 

 hydroxide when .5 per cent, sodium carbonate 

 had been added to the medium. 



One per cent, sodium carbonate added to 

 the neutralized agar medium did prevent the 

 germination of the spores. 



Red gum boards dipped in a 7 per cent. 



