286 



THE NORTH AMERICAN SLIME-MOULDS 



The capillary theory may not, probably does not, play part in 

 every case. It would seem that a stemonitis, for example, must owe 

 the rise of the spore-plasm to the play of different machinery. Bre- 

 feldia, p. 154 above, may offer suggestion. 



g. On page two of the introductory section of this volume men- 

 tion is made of the variety of colors shown in the vegetative phases of 

 the organisms we study. This fact is patent to all observers ; but the 

 identity of the Plasmodium making the display must be ascertained 

 by painstaking or prolonged and repeated observations. This for the 

 reason that, as I am convinced, only in comparatively few cases is the 

 color unchanged during the life-history of a given fructification. It 

 may sometimes change from hour to hour as development proceeds. 

 The color designated in the descriptive pages of this work is pre- 

 sumably, unless as otherwise set out, that immediately preceding that 

 of the maturing fruit. 



As suggestive, and as, it is hoped, contributory to better knowledge 

 of this phase of our subject a list of species is here subjoined as pre- 

 sented by my colleague. Professor Morton E. Peck of Oregon, who 

 has given unusual attention to this particular investigation. 



Species 

 Physarum sinuosum . 

 PJiysarum serpula . . 

 Physarum virescens . . 

 Physarum cinereum . . 

 Physarum didermo'ides 

 Physarum notabile 

 Physarum globuliferum 

 Physarum leucopus 

 Physarum pulcherrimum 

 Physarum flavicoinum 

 Physarum <viride . . . 

 Physarum luingatense 

 Badhamia orbiculata . . 

 Physarella oblonga . . 

 Mucilago spongiosa . . 

 Didymium crustaceum 

 Didymium squamulosum . 

 Didrrma flor'iforme 

 Stemonitis fusca . . , 



Plasmodium Colors 

 light grey, nearly white, ivory white 

 greenish-yellow; yellow 

 pale greenish-yellow; yellow 

 watery grey, becoming white ; pallid 

 watery grey, becoming white; blue-white 

 pure white 



greenish-yellow; yellow 

 light grey 

 dark red 



greenish or brownish yellow 

 clear yellow 



at first grey, then pure white 

 pale yellow, passing to white 

 brilliant yellow 

 watery grey, then white 

 white 



pale grey, watery white 

 grey tinged with yellow 

 white passing through blue to black 



