. The biology of the Protozoa. Protozoa; Protozoa. A B Fig. 68.—Types of Peridinidse with cellulose shells composed of plates. A, Goniodoma acuminatum Ehr.; B, Gomjaulax Kof. {F) transverse furrow with epitheca above and hypotheca below. {A, after Schiitt; B, after Kofoid.) (6) Motile Organoids.—The organoids by which Protozoa move are to be considered as modifications of the cortex, although some t^'pes, as shown in the preceding chapter, are derived in part from internal kinetic elements (flagella and some pseudopodia). Three main types are distinguishable—flagella, pseudopodia and ciHa, eac
. The biology of the Protozoa. Protozoa; Protozoa. A B Fig. 68.—Types of Peridinidse with cellulose shells composed of plates. A, Goniodoma acuminatum Ehr.; B, Gomjaulax Kof. {F) transverse furrow with epitheca above and hypotheca below. {A, after Schiitt; B, after Kofoid.) (6) Motile Organoids.—The organoids by which Protozoa move are to be considered as modifications of the cortex, although some t^'pes, as shown in the preceding chapter, are derived in part from internal kinetic elements (flagella and some pseudopodia). Three main types are distinguishable—flagella, pseudopodia and ciHa, each of which is sufficiently distinct from the others to furnish a natural basis for chissification of the Protozoa, a basis of classi- fication which Dujartlin first employed to create the three great groups les flageUes, ks rhizopodes, and les cilies. Each type is sub- ject to man\' variations, due to inherent differences in the motile organoids themselves, or to fusion in various ways leading to struc- tures of considerable complexit\'. It is extremely difficult to decide whether fiagella or pseudopodia are the more primitive in type. From most general text-books on Zoology we learn that the matter admits of no question, and are taught that the pseud()i)odium is the most primitive form of motile organ in the animal kingdom. This certainly has been the most widely accepted view. Many a generalization referring to Protozoa, however, which has found its way into general works on Biology, appears to have been drawn from the conditions in some one organ- ism which is conspicuous by reason of its abundance and ease of study. It would sometimes appear, indeed, that the common species of Parariiecium and Ainoehaproteus, to many general writers, constitute the Protozoa. This seems to be the case with the problem of pseudojjodia and fiagella, the argument being that a pseudopo-. Please note that these images are extracted from scanned page images that may have been digitally enhan
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