MTXOMYCETES. 5 



for their vegetation (most Fungi require light for fructification). 

 The Myxomycetes, Bacteria, and Fungi derive their nourish- 

 ment either as saprophytes from dead animal or vegetable matter, 

 or as parasites from living animals or plants (hosts), in which they 

 very often cause disease. 



A remark, however, must be made with regard to this division. Among the 

 higher plants so much stress is not laid upon the biological relations as to divide 

 them into " green " and " non-green"; Cuscuta (Dodder), a parasite, is placed 

 among the Convolvulaceae, Neottia and Corallorhiza, saprophytes, belong to the 

 Orchidaceas, although they live like Fungi, yet their relations live as Algae. In 

 the same manner there are some colourless parasitic or saprophytic forms among 

 the Algae, and stress must be laid upon the fact that not only the Blue-green Algae, 

 but also the Bacteria, which cannot assimilate carbonic-acid, belong to the Algae 

 group, Sehizophyceae. The reason for this is that systematic classifications must 

 be based upon the relationship of form, development, and reproduction, and from 

 this point of view we must regard the Bacteria as being the nearer relatives of 

 the Blue-green Algae. All the Thallophytes, which are designated Fungi (when 

 the entire group of Slime-Fungi is left out), form in some measure a connected 

 series of development which only in the lower forms (Phycomycetes) is related 

 to the Alga?, and probably through them has taken its origin from the Alg83 ; the 

 higher Fungi have then developed independently from this beginning. The 

 distinction of colour referred to is therefore not the only one which separates the 

 Alga? from the Fungi, but it is almost the only characteristic mark by which 

 we can at once distinguish the two great sub-divisions of the Thallophytes. 



The first fo>ms of life on earth were probably " Protistae," which had assimi- 

 lating colour material, or in other words, they were Algae because they could 

 assimilate purely inorganic food substances, and there are some among these 

 which belong to the simplest forms of all plants. Fungi and Slime-Fungi must 

 have appeared later, because they are dependent on other plants which assimi- 

 late carbon. 1 



Sri-Division I. MYXOMYCETES, SLIME-FUNGI. 



The Slime-Fungi occupy quite an isolated position in the 

 Vegetable Kingdom, and are perhaps the most nearly related to 

 the group of Rhizopods in the Animal Kingdom. They live in and 

 on organic remains, especially rotten wood or leaves, etc., on the 

 surface of which their sporangia may be found. 



They are organisms without chlorophyll, and in their vegetative 

 condition are masses of protoplasm without cell- wall (plasmodia) . 

 They multiply by means of spores, which in the true Slime-Fungi 2 



1 According to the recent investigations of Winogradsky some micro-organisms 

 (Nitrifying-bacteria) can build organic from inorganic matter. Sachs' hypothesis 

 that the first organisms must necessarily have contained chlorophyll is there- 

 fore untenable. 



2 Myxogasteres, Engler's Syllabus, p. 1. 



