42 Objects for the Microscope. 



CHAPTER III.. 



INFUSORIAL EARTHS. 



THESE slides, which require high power and a good 

 microscope to examine, consist of specimens of Diatomacese 

 from different part's of the world. Their value is in pro- 

 portion to the knowledge of their possessor concerning the 

 DiatomaceaB generally and particularly. The Diatom aceae 

 are minute vegetable forms, called also " brittleworts," 

 from the almost unavoidable separation of their cells or 

 frustules in handling them. Long have they caused dis- 

 putes as to their animal or vegetable nature. Very eminent 

 naturalists, such as Ehrenberg, seeing them gifted with 

 spontaneous motion, the little golden Naviculse sailing 

 slowly across the field of vision, apparently turning back 

 when meeting with an obstacle, or whirling gently round 

 as if by their own will, decided that they were surely 

 animal, and classed them with the Infusoria, which are 

 microscopic animals, found in salt and fresh water. But 

 later researches and patient investigation have placed 

 beyond doubt the vegetable nature of these beautiful crea- 

 tions, to whose variety there appears no limit. 



As the wondering astronomer discovers the infinite 

 worlds revealed in unfathomed space, and sees star after 

 star arise in countless myriads within the dim and distant 

 nebulaB, as his mind bows down overwhelmed by the sense 

 of the omnipotent Creator's dominion and guidance of all 

 those glorious orbs, even so the microscopist bends in 

 astonished awe before the infinitude of God's works in the 

 uncountable varieties and exquisite beauty of the minute 

 Diatoms. 



BILIN SLATE. Wherefore are they thus highly wrought, 

 and why in such abundance ? Take up that slide of Bilin 

 slate, and know that in one single cubic inch 40,000 millions 

 of these delicate forms are found ! 



