ADVANCE IN LOWER PLANT AND ANIMAL FORMS 



17] 



PLATE LXX 



PLATE LXX (continued) 



Fig. 32.— Colony of two monads (Dendromonas virgaria, Weisse) dividing by longitudinal fission. 



F16. 33.— Adult colony of monads [Gladomma laxmn), x 1000. Eesemljles small slirub in its general aspect. 



Fig. 34. — A monad dividing by longitudinal fission, x 1500. n, Nucleus ; cv, contracting vesicle. 



Fig. 35.— A monad dividing by transverse fission, x 1500. These cleavages are at the root of development and differentiation 

 (the Author). 



Figs. 36, 37, 38, 39, and 40. — Free-swimming luonads {Spiromonas anciustata) with their bodies in three cases variously twisted 

 X 1500. The spiral movements of free-swimming monads mark a new and important departure (the Author). 



Fig. 41.— An erect branching colony stock (Anthophysa vegetans, Miill.) with thiee terminal monad clusters, x 400. The branching 

 appearance presented by this figure resembles that seen at Figs. 31, 32, and 33. 



Fies. 42 and 43. — Two specimens of Tetramitus descissus, x 1500. 



Fig. 44. — Head of colony stock of zooids (Anthophysa sodalis), x 1500 (Biitschli). Presents flower-like rosette. 



Fie. 45. — Young animalcules (Tetramiitus rostratus), x 650. 



PLATE LXXI 



This plate illustrates the power possessed by animalcules of changing shape at pleasure ; of dividing longi- 

 tudinally and transversely ; and of assuming spiral shapes structurally and when moving. It also shows advance 

 in organisation ; the flagella being increased in number, there being a superior vibratile set employed for catching 

 food, and an inferior set used for fixing or anchoring purposes ; hair-like setee and ciUa also make their appear- 

 ance. Advance in structure and greater functional range proceed pari passu. 



Figs. 1 to 11 inclusive.— Animalcule (Trepomowas a^ife) as seen from various points with body straight and twisted, x 650. At 

 3. 7 and 8 the animak " •-■--■ ..-r,. ,, ., , . , •. ._j _.i_^_i_i_ , 



the arrows in this figure i 



Figs. 7 and 8 the animalcule is dividing by longitudinal fission. At Fig. 11 the nucleus (n), and contractile vesicle (cv), are shown: 

 I indicate the direction of the circulation of the endoplasm (Stein, Perty, and Biitschli). The figures illustrate 



