12 



HUTCHINSON'S POPULAR BOTANY 



of their coats (properly, walls] of cellulose, were simply naked masses of 

 protoplasm. In many-celled plants, where cell-walls are always formed, 

 the .protoplasm may be used up in the thickening of the wall or transferred 

 to other parts of the plant : but in such cases what remains is still called 

 a cell. 



The term cell appears to have been first used in a botanical connection 

 by the English microscopist, Robert Hooke. Writing in ,1665, he says : 

 u Our microscope informs us that the substance of cork is altogether filled 

 with air, and that that air is perfectly enclosed in little /boxes or cells, 

 distinct from one another." At that time, and for many years after, 

 the " little boxes " were considered the essential part of the plant : indeed. 



FIG. 25. 



BACILLI : SINGLE-CELLED FUNGI. 



FIG. 26. 



These microscopic plants belong to the division known as Schizomycetes or " Fission " Fungi, from their habit of 



increasing their numbers by dividing into two. The first is the Comma Bacillus, which produces Asiatic cholera. 



The second is the Bacillus of Bubonic Plague. Its long appendages are the flagella by which movement is 



effected. Highly magnified. 



it was not till the last century, when Schleiden, Schwann, and Mohl in 

 Germany, and Lionel Beale in our own country, proceeded to look into 

 the little boxes, that the maintenance of a contrary view became possible. 

 Then began, indeed, the study of Biology, the greatest though youngest 

 of the sciences, which has grown to such wonderful proportions in recent 

 years, though it must still be regarded as almost in its infancy. 



Until the discovery was made that the protoplasm is the essential 

 constituent of the cell, our knowledge in vegetable physiology could 

 make but slow advances, and a great mass of facts connected with the 

 anatomical structure of plants which the microscope had brought to 

 light, though interesting in a general way, could have but little scientific 

 value. There was much, for instance, to gratify one's taste for the 

 marvellous in the statement that the surface of a square inch of cork 



