92 THE MYXOMYCETKS. 



creeps about by throwing out pseudopodia, while it still retains 

 its flagellum, and in this state it resembles the Infusoria 

 known as Mastigamoeba and Reptomonas. The flagellum is then 

 absorbed, and the creature becomes extremely similar to an ordinary 

 amoeba. Both in this stage and the preceding it increases by fission, 

 and takes in solid particles of matter, and apparently extracts the 

 nutriment from them just as an amoeba does. This point seems to be 

 set at rest by the very definite observations that have been made, and 

 is acknowledged by Sachs, who places the Myxomycetes among the 

 Fungi, as much as by Saville Kent, who claims them for the Protozoa, 

 although some mycologists appear to regard the statement as incorrect.* 

 De Bary and Cienkowski both witnessed the ingestion of solid food. 

 Saville Kent fed his specimens upon carmine, and after a time found 

 the solid particles embedded in the protoplasm, just as we find diatoms 

 in an ordinary amoeba. 



It may be as well to pause here for a while to point out the 

 significance of these facts. The capacity of taking in solid food 

 is usually considered the prerogative of animals ; plants imbibe 

 their food in a liquid condition ; and Saville Kent, who insists 

 that the statement in this naked form furnishes a distinct line of 

 demai'cation between the Animal and Vegetable Kingdoms, considers 

 that this one point, well established, decides the question. But if we 

 consider the difference more deeply, I do not see that it affects the 

 controversy in any way. Why do plants usually imbibe their food in 

 a liquid form ? Because the protoplasm of plants has the habit of 

 surrounding itself with a wall of cellulose, in which are no pores 

 capable of admitting solid particles of even microscopically visible 

 size. Animals on the contrary have a mouth, by which they can take 

 in particles of various sizes according to the capacity of the opening, 

 or else, as in the Rhizopoda, their protoplasm is not surrounded by an 

 impermeable wall. In either case, however, the nutriment is reduced 

 to a liquid form, by digestion, before it actually enters and becomes a 

 part of the substance of the body. 



If, then, we should meet with a plant in which the protoplasm was 

 naked, we should expect it to possess also the power of ingesting solid 

 food. It need not be said that naked protoplasm is inet with in the 

 Vegetable Kingdom, as in all kinds of spermatozoa or antherozoids, and 

 the zoospores of Algae, and you will remember the curious observations 

 of Francis Darwin upon the protrusion of naked protoplasmic filaments 

 from certain glands on the leaves of the Teasel, and also from the 

 cells of the stem of AijariciDi muscarius.i The real difficulty is 

 to explain why these fungi do not develop cellulose coats to their 

 protoplasm, not to account for their taking in solid food. The 

 flagellum, too, is nothing more than a minute thread of protoplasm 

 projected from the body, and is possessed alike by the gonidia of 

 Volvox, and most zoospores and antherozoids. 



* Grevillea, ix., 43. 



I " Quarterly Journal of Microscopical Science," 1878, pp. 74-82. 



