158 THE VICTORIAN NATURALIST. 



on through loo generations on solid blood serum apparently 

 retain all the properties of their original stock, and produce 

 general tuberculosis in the usual way when inoculated. Some- 

 what analogous phenomena are seen in bacilli obtained from 

 various animals. For instance, tubercle bacilli taken from a 

 human patient and inoculated into a cow will set up " acute 

 general tuberculosis," the tubercles and the bacilli being found 

 in nearly all the organs and tissues of the body. But bacilli 

 taken from a case of bovine tuberculosis, set up almost invariably 

 a special bovine form of the disease, in which the lungs, and 

 especially the pleura, are the parts attacked, and, microscopically, 

 the new formations have a very different appearance from ordinary 

 human tubercles. 



In the case of the tetanus bacillus, that which causes lock-jaw, the 

 virulence of the culture is kept up only when they are grown in 

 the absence of oxygen. The presence of this element destroys the 

 power of even pure cultivation of the organism after a very 

 short time. Many other facts of a somewhat similar character 

 are known, and they appear to throw some considerable light on 

 the question of the " Origin of Species," for the differences in 

 organisms which can thus be artificially produced are quite as 

 great as those which are held to differentiate one species from 

 another. The protoplasm of these lowly forms of life seems to 

 be very plastic. When inoculated under conditions which are 

 not absolutely favourable to their growth, those best adapted to 

 the conditions survive and grow. The second inoculation will 

 contain a larger proportion of these, and so in the course of a few 

 generations the descendants may have varied greatly from the 

 original stock. 



NOTES ON NUYTSIA FLORIBUNDA, 



By Mr. W. Webb, of King George's Sound (furnished in response 

 to some questions from Baron von Mueller). 



We can find thousands of what appear at first sight to be seed- 

 lings, but on tracing the roots we always find them growing from 

 the roots of parent trees, and therefore we think these supposed 

 seedlings are nothing more or less than suckers. Up to the 

 present we have not been able to find the roots of the tree 

 attached to anything ; they shoot out in all directions and for 

 great distances, but never penetrate the soil deeply, but are 

 always found some few inches below the surface ; in this manner 

 they may — and probably do — receive their sustenance from 

 ■decaying vegetable matter, such as the roots of the numerous 



