2 BRITISH FUNGI 



fungi arc true }:)lauts, but owint;- to the absence of cliloropliyll, 

 require organic food. Fungi are not unique in tlie \'egetable King- 

 dom in this matter. ]\Iany plants belonging to different natural 

 orders, that once had chlorophyll, have for some reason become 

 devoid of chloroph}'ll, and consequently have to obtain organic 

 food eitlier as parasites, as the broom-rapes, or as saprophytes, as 

 the birds'-nest orchid. 



The fungi as a group are considered as ha^•ing evoh-ed from the 

 algs, or seaweeds ; hence, as would be expected, the oldest and most 

 primitive types of fungi are aquatic in habitat, and in many in- 

 stances closely resemble certain alga; in structure, differing mainly 

 from alg?e in the absence of chlorophyll, so at this stage of evolution 

 it may be said that fungi are alg?e devoid of chlorophyll. This, of 

 course, implies a change of food, as, owing to the absence of chloro- 

 phyll, our fungi cannot utilize inorganic food. Another point of 

 importance to remember is the fact that, in the primitive fungi, 

 the reproductive bodies or spores possess the power of spontaneous 

 movement, that is, they can, by the aid of one or more slender 

 prolongations of the substance of the spore, called cilia, swim about 

 for some time in the water into which they are liberated. Such 

 reproductive bodies are called zoospores. This power of spon- 

 taneous movement enables the zoospores to reach places suitable 

 for germination and the production of a new fungus. Up to the 

 present phase of evolution it is only possible to consider the fungi 

 as other than modified algas, in the sense that a mistletoe or a 

 broom-rape is off the normal track of a typical ffowering plant. It 

 was when the fungi commenced to leave their original aquatic 

 habitat and encroach on dry land, that the first really important 

 modifications of structure were initiated. So long as fungi re- 

 mained aquatic organisms, zoospores were the ideal type of repro- 

 ducti\'e bodies, but in endeavouring to extend their range on dry 

 land, they were very much handicapped by only possessing zoo- 

 spores, winch necessitated the presence of water for their dispersion. 

 It may be mentioned at this point, that in the ancient aquatic fungi 

 the reproductive bodies or zoospores were in most instances the 

 result of fertilization, or due to a sexual process. Once established 

 on dry land, a new form of reproducti^'e bodies was graduall}^ 

 evolved, of an entirely asexual origin, called conidia. These conidia, 

 or asexual reproductive bodies, are in most instances exceedingly 

 minute, dry, and so constructed that their dispersion could be 

 effected by wind, insects, and -other aerial agents. Now it was just 

 the evolution of the conidial form of reproduction, capable of being 

 scattered by wind, that enabled the fungi to gradually take 

 possession of every portion of dry land inhabited by higher plants, 

 from which they could obtain the required food. From the above 

 account it will have been gathered that the fungi, at the time of 

 their evolution from the algae, and on their first endeavours to gain 



