MICROSCOPIC FOKMS OF ANIMAL LIFE. 33 



ing composite fabrics, in some of which the calyces follow one another in 

 linear series, whilst in others they take on a ramifying arrangement. 

 While some of these composite organisms are sedentary, others, as Dino- 

 bryon, are free-swimming. 



426. Two solitary Flagellate forms, Anthopliysa and Anisonema, 

 may be specially noticed as presenting several interesting points of resem- 

 blance to the peculiar type next to be described; the most noticeable 

 being the presence of a distinct mouth, and the possession of two different 

 motor organs one a comparatively stout and stiff bristle of uniform 

 diameter throughout, which moves by occasional jerks; and the other a very 

 delicate tapering flagellum, which is in constant vibratory motion. If, as 

 appears from the recent observations of Biitschli, the well-known Astasia 

 of which one species has a blood-red color, and sometimes multiplies to 

 such an extent as to tinge with it the water of the ponds it inhabits has 



Fig. 296. 



osiga umbellata .-colony-stock, springing from single pedicel tripartitely branched. 



a true mouth for the reception of its food, it must be regarded as an 

 Animal, and separated from the Euglena (with which it has been gener- 

 ally associated), the latter being pretty certainly a Plant belonging to the 

 same group as Volvox. 1 



427. There can be no longer any doubt that the well-known Nocti- 

 luca miliaris to which is attributable the diffused luminosity that fre- 

 quently presents itself in British seas is to* be regarded as a gigantic 

 type of the ' unicellular ' Flagellata. This animal, which is of spheroidal 

 form, and has an average diameter of about 160th of an inch, is just large 

 enough to be discerned by the naked eye when the water in which it may 

 be swimming is contained in a glass jar held up to the light; and its tail- 

 like appendage, whose length about equals its own diameter, and which 

 serves as an instrument of locomotion, may be discerned with a hand- 



1 See the Memoir by Prof. Biitschli, in "Zeitschrift f. Wissensch. Zool.." Bd. 

 xxx.; of which an abridgment (with Plate) is given in " Quart. Journ. Microsc. 

 Sci.," Vol. xix. (1879), p. 63. 

 3 



