A 22 rilYSICAL GEOGRAPHY. 



were erected into a family by themselves, and provisionally placed in the 

 animal kingdom. Very soon, however, it was observed that they pos- 

 sessed characters inconsistent with animals as then known, but more 

 nearly allied to plants. For this reason they were soon removed to the 

 vegetable kingdom, and, after a time, ranked as algae, or water-plants 

 which do not produce evident flowers. Yet there have been, and in fact 

 still are, observers who think that these organisms were improperly 

 removed from amongst the animals, and the consequence has been that, 

 for a few years, they vacillated between these two kingdoms. Py far the 

 greater number of naturalists, however, have come to consider them as 

 plants, and so they have rested up to a very late date. It has been within 

 the last six or eight years that their true position has apparently been 

 determined by a German naturalist named Haeckel, who considers that 

 they possess characteristics which qualify them for a position, along with 

 a few other minute forms of life, in a group separated alike from animals 

 and vegetables, and to which he has given the name of Protista. With- 

 out, at the present time (for it would be out of place in a publication of 

 the character of the present), going into the consideration of the reasons 

 which have influenced the eminent German naturalist in his conclusions, 

 suffice it that the author of this sketch coincides with him in his opinion, 

 and considers the diatomacea) to be neither animals nor plants, but 

 Protista. 



The diatomaccno are inhabitants of both fresh and salt water, as well 

 as that which is brackish by reason of its being subjected to the periodi- 

 cal influx of the water of the ocean, or that from springs and streams. 

 They live in many cases attached to submerged objects, such as plants, 

 rocks, or wood-work ; but some species appear to be free, and unattached 

 to anything. It is, however, likely, as has been shown by the present 

 writer, that all of them spend a portion of their lives attached to sub- 

 stances below the surface of the water, whilst they have periods of free- 

 dom when they swim about, and in this way disseminate the species. 

 Although we find them inhabiting both fresh and salt water, yet it would 

 seem that there are certain forms which will not thrive in both of 

 them. Thus, we find certain well marked species which would seem to 

 be confined to the ocean, whilst others are only to be seen in running 

 fresh water, and still others exist solely in quiet lakes. However, so little 



