THE VEGETABLE AND ANIMAL KINGDOMS. 149 



even uncertain whether this matter will reproduce its like, and 

 whether it is not a mere representation of the vital principle 

 of vegetation, capable of being called into action either as a 

 Fungus, an Alga, or a Lichen, according to the particular con- 

 ditions of heat, light, moisture, and medium, in which it is 

 placed ; producing Fungi upon dead or putrid organic beings ; 

 Lichens upon living vegetables, earth, or stones ; and Algae 

 where water is the medium in which they are developed. 

 Kiitzing endeavours to maintain the following propositions 

 connected with this subject : 1st, the formation of organic 

 matter can only take place by means of the previously dis- 

 solved elements of other organic principles ; 2nd, simple glo- 

 bules, such as Cryptococcus, Palmella, and Protococcus, can 

 give birth to different formations, according to the influence of 

 light, air, and temperature ; 3rd, we must regard all the forms 

 of lower algae as vegetations of a very simple structure, and 

 distinguish them from each other, notwithstanding that in 

 certain circumstances they may raise themselves to vegetations 

 of a higher form ; for, in other circumstances, they can exist 

 and multiply independently ; 4th, the same formation may be 

 produced by primitive formations of altogether different kinds." 

 " It has been said," adds Dr. Lindley, " that Algae are aquatics, 

 while Lichens and Fungi are terrestrial ; but Fungi ivill deve- 

 lope in water, when they assume the form of Algce" 1 Un- 

 doubtedly eight so-called genera of fungi are now set down as 

 only variations of one plant (Thelephora sulphurea), arising 

 from peculiar conditions of culture. 



Even in higher departments of the vegetable kingdom, the 

 revolutions have been very remarkable. In a recent memoir 

 on the Coriiferse, six so-called species of pine are wound up 

 into one. The cowslip, primrose, oxlip, and polyanthus, which 

 were always regarded as distinct species, are now found to be 

 producible from one set of seeds, under various conditions ; 

 they are radically one plant. So also " the clove, pink, and 

 carnation are only varieties of a flower growing among the 

 ruins of some of our old castles, the Dianthus caryophyllus." 

 The artichoke of the garden and the cardoon (a kind of thistle) 

 of the South American wild, are held as distinct species in all 

 botanical works ; yet the artichoke, in neglect, degenerates into 

 the cardoon. 2 The ranunculus aquatilis and the ranunculus 

 hederaceus are, in like manner, set down as distinct species ; 



1 The Vegetable Kingdom, 8vo, 1846, p. 5. 

 2 Darwin's Journal of a Voyage Kound the World. 



