104 



THE AMERICAN MONTHLY 



[June, 



nor the tyrant masters play anything 

 like the pait assigned them by the 

 adherents of this theory. 



The second objection pointed out 

 by Mr. Crombie is to the effect that 

 there ' are neither fungal-mycelia nor 

 algal-colonies in the structure of 

 lichens,' for if there •were, as he very 

 clearly shows, we should expect to 

 find them in similar localities ; but, as 

 every one very well knows, quite the 

 reverse is true. 



No one, for instance, would think 

 of searching for algte upon the bare 

 and exposed surface of a mountain- 

 top, where lichens are in abundance ; 

 nor, vice versa^ would we expect to 

 find lichens where algai are in pro- 

 fusion. 



But, notwithstanding a certain su- 

 perficial resemblance between the 

 hyphie of lichens and of fungi, their 

 structure and character are entirely 

 different. 



' The hyphte of lichens are peren- 

 nial, firm, with thick walls, pene- 

 trated by lichenin, imputrible, and 

 not dissolved by hvdrate of potash. 

 On the other hand, the hvphoid- 

 mycelia of fungi are caducous, very 

 soft, with thin walls, not at all 

 amylaceous, readilv putrifying on 

 maceration, and, on the application 

 of hydrate of potash, immediately 

 becoming dissolved.' It is shown 

 by this that there are irreconcil- 

 able physiological differences which 

 should seem to preclude the dual 

 nature of these organisms. But, 

 beyond these, there is another very 

 important point made by the oppo- 

 nents ot the Schwendenerian hy- 

 pothesis, viz., that if the gonidia are 

 algae, we should expect to find them 

 all in the free state ; but this is by no 

 means true, the gonidia, for instance, 

 oi NcBtrocymbe, PhylUscuni^ Mala- 

 nornis^ and others, have not yet been 

 found elsewhere than in the lichen- 

 thallus. But all this array of facts, 

 important as it is in its bearing on 

 the case, leaves us still in doubt as 

 to the real nature of these organisms. 

 The question is merely shifted from i 



one horn of the dilemma to the other, 

 for, as was stated in the beginning of 

 this paper, unless we can demonstrate 

 that the gonidia have their origin in 

 the lichen-thallus, we might as w^ell 

 accept one theory as another. The 

 proof, however, of their thalline ori- 

 gin, Mr. Crombie seems to have ad- 

 duced. 



As was before stated, the artificial 

 cultivation of lichen-spores can rarely 

 be carried beyond a certain loosel}' 

 cellular state, w^hen, the exact con- 

 ditions of nature failing to be repre- 

 sented, the cultures are destroyed. 

 But, fortunatel}', by carefully exam- 

 ining the plants in a state of nature, 

 we are able to find them in all con- 

 ditions from the freshly germinating 

 spore to the mature plant. This i^ 

 particularly the case with those 

 species growing upon dry rocks, 

 where there is no substratum to min- 

 gle with and obscure them. 



Air. Crombie uses the following 

 language in description of the evolu- 

 tion of the gonidia : ' On germina- 

 tion, as may easily be seen in spore 

 culture, the spore sends forth from 

 the endosperm a germinating filament 

 or filaments called the prothallus. 

 This speedily passes into the hypo- 

 tliallus. The hyphre thus produced 

 contain lichenin from the very first, 

 and in other respects present the 

 distinctive characters already men- 

 tioned.' Now is the time, according 

 to Schwendenerism, when we might 

 expect to find the hyphae going out 

 in quest of algce, which they might 

 lay hold of and imprison in their 

 meshes. As a matter of fact, how- 

 ever, we never do, for the hyphae 

 grow straight forward, never turning 

 to the right or left in quest of the 

 algge, nor would they find them if 

 they did, for not a vestage of an alga 

 can be discovered in such a habitat. 

 Yet in a slightly more advanced stage 

 the gonidia are found in the thallus 

 in abundance. Whence and how 

 came they } Says Mr. Crombie : 

 ' On a further inspection of the speci- 

 mens you will readily perceive upon 



