38 ] The Classification of Lower Organisms 



sey, 1905). The flagella of nucleate organisms are not homologous with those of 

 bacteria; they are much larger and of much more complicated structure. 



The origin of flagella was apparently associated with a simplification of the system 

 of photosynthetic pigments, by the loss of chromoproteins, leaving systems of chloro- 

 phylls and carotinoids. The association of these two courses of evolution may have 

 been merely coincidental; Tilden suggested the idea that the loss of chromoproteins 

 may have been occasioned by increasing illumination of the waters of the face of the 

 earth. 



Organisms of the body type of solitary walled cells, having chlorophylls and caro- 

 tinoid pigments but not chromoproteins, and producing flagellate reproductive cells, 

 appear to have undergone radiating evolution, producing a wide variety of types of 

 organisms, distinguished by different specific chlorophylls and carotinoids, different 

 types of flagella, and different specific metabolic products. The types of flagella oc- 

 curring in nucleate organisms are here particularly to be noted. 



Loeffler (1889), in the original publication of the standard method of staining the 

 flagella of bacteria, remarked that he had applied this method also to certain larger 

 organisms. He found that the flagellum of Manas bears numerous lateral appendages, 

 and that the cilia of a certain infusorian bear solitary terminal appendages. Loeffler's 

 method is difficult, and has not been much used. Fischer (1894) used it and coined 

 terms, Flimmergeisseln and Peitschengeisseln, designating structures of the respective 

 types seen by Loeffler. Petersen (1929), having applied Loeffler's method to a reason- 

 able variety of flagellates, introduced refinements of terminology. Flagella of the 

 type of the larger flagellum of Monas (the organism bears also a minute simple flagel- 

 lum) became allseitswendige Flimynergeisseln; those of Euglena, which bear a single 

 file of appengages, became einseitswendige Flimmergeisseln. 



Deflandre ( 1934) devised a different method for seeing the appendages on flagella, 

 and substituted, for the Teutonisms just quoted, French terms based on Greek. These 

 may be Anglicised as follows. ( 1 ) The acroneme flagellum bears a single terminal 

 appendage. The flagellum without appendages is said to be simple; so far as it ap- 

 pears among nucleate organisms, it appears to be a variant of the acroneme type. 

 (2) The pantoneme flagellum bears appendages on all sides. (3) The pantacroneme 

 flagellum bears both terminal and lateral appendages. It is a rarity, known only in 

 the collared monads, and may be supposed to be a variant of the pantoneme type. 

 (4) The stichoneme flagellum bears a single file of appendages. 



The point in which Barkley and Rothmaler take exception to the limits here given 

 to kingdom Protoctista is this, that they include in this kingdom the green algae. In 

 the present work, scant attention is given to organisms whose plastids are bright 

 green, containing chlorophylls a and b, carotin, and xanthophyll, and no other pig- 

 ments; whose motile stages have acroneme flagella, more than one (usually two), 

 and equal; and which produce essentially pure cellulose, true starch, and sucrose. 

 These organisms represent the undoubted evolutionary origin of the higher plants; 

 a classification which attempts to represent nature includes them necessarily in the 

 plant kingdom. 



Rothmaler set up a system of only four phyla, being the red organisms, basically 

 without flagella; those which are typically yellow to brown, having pantoneme flagel- 

 la; those with acroneme flagella, including the green algae; and the euglcnid group, 

 which have stichoneme flagella. The non-pigmented Protoctista were distributed 

 among these groups. The system appears unsound by the fact that large blocks of 

 non-pigmented organisms are placed where only portions of them belong. 



