50 Infusoria : What are they? 



the student of Infusoria is undoubtedly furnished by weed- 

 grown ponds. From these he may always expect to reap an 

 abundant harvest. Fragments of the weeds, more ^particularly 

 the finely divided varieties, such as MyriophijUum, B.anunculuSy 

 and the rootlets of Duckweed (Leuma), should be placed in a 

 bottle and examined carefully for colony-stocks of the 

 ** Trumpet" and "Bell" animalcules, which may be easily 

 detected with the assistance of a pocket lens, and may even 

 be recognised as flocculent growths upon these plants with 

 the unaided vision. Many of the fi'ee Ciliata, when abun- 

 dantly developed, will also be rendered visible as glistening 

 specks progressing through the water with that peculiar 

 locomotive action distinctive of its kind. Excepting in the 

 case of the social FAUjlencB, and a few other types, wdiose 

 presence, as already mentioned, lends a distinct coloration to 

 the water, the collection of the Flagellata is pre-eminently an 

 act of faith, and not of sight. Notwithstanding that the 

 weeds gathered may appear to the unassisted eye, or even as 

 examined with the pocket lens, completely barren, they may 

 on submission to the higher powers of the microscope be 

 found to be teeming with flagelliferous types. The collector, 

 moreover, should be advised not to immediately throw away 

 what appears on a preliminary investigation to be an unpro- 

 ductive gathering. Such gatherings often contain an abun- 

 dance of latent germs, which after an interval of a few days 

 develop luxuriantly on the surface of the plants, or on the 

 sides of the receptacle that contains them. Two of the first 

 and most remarkable flagellate types yet met with, PJdpido- 

 dendron Huxleyi and Spongomonas sacciihis, as delineated in 

 the exhibited plates (' Manual of the Infusoria,' pi. xvi., figs. 

 4-9, and ]}l. xii., figs. 17-23), were thus obtained fortuitously 

 by myself from bog-water collected on Dartmoor, and which, 

 as gathered and submitted to preliminary examination, be- 

 trayed no trace of abnormal infusorial life. Within a few 

 days, however, little rust-red patches made their appearance 

 upon the sides of the bottle, and developed within a brief 

 interval into the colony- stocks, represented in the plates 

 submitted ; these were not only distinctly visible to the 



