106 INTRODUCTION TO CRTPTOGAMIC BOTANY. 



87. It is not the object of a work like the present to give a 

 history of every systematic change, or of every step by which 

 we have arrived at the present state of knowledge, nor do I 

 feel bound to make room for more modem systems, which 

 have departed from the unity and symmetry which were first 

 sketched out by Agardh* the elder, and have been successively 

 improved by his son, and by our countryman, Dr. Harvey. 

 The modern French Algologists, as Montague, Decaisne, &c., 

 have also thrown much light upon the subject, but they seem 

 to me to lay too much stress upon the zoospores, in their 

 arrangements. No one appears to feel the real affinities 

 of Algae better than Dr. Harvey, and there is surely no one 

 one who has had such opportunities of examining them under 

 every variety of climate and locality. The main divisions 

 which he has proposed are three : 



1. MELANOSPERMEiE (spOTCS oUve). 



2. RhodospermEjE (spores red). 



3. Chlorosperme^ (spores green). 



88. That these divisions are as certainly founded in nature as 

 those of Algals and Mycetals is beyond doubt ; but whether the 

 names or the characters which those names indicate, are the best 

 that might be chosen, or whether individual genera are rightly 

 disposed, is another question. The difficulties are most glaring 



* According to Agai-dh's Systema Algarum, published in 1824, the 

 arrangement is, by analogy with the development of Phjenogams : 



1. Hyalinje (Diatomeas, &c.) = Radix. 



2. Viridea (Confervse, &c.) = Herba. 



3. Purpureas (Floridese, &c.) = Flos. 



4. Olivaceas (Fucoidese, &c.) = Fructus. 



According to this system the genera were arranged, but the whole 

 was too fanciful to be permanent. I know of few things to be so much 

 deprecated in science as these fancies. Arguments in favour of design 

 in the work of creation, are only enfeebled by such puerilities, as by all 

 other extravagance and exaggeration (compare above, p. 39). The first 

 division was gradually merged in the second, and, with modifications as 

 to the true affinities of species, the divisions are the same with Harvey's. 

 Lamouroux, in 1813, laid the foundation by the distinction of Fucacea 

 and Floridm. Agardh was, however, in all probability but slightly 

 acquainted with Lamouroux's Memoirs, or if familiar with them, he did 

 not pay them the attention they deserved. 



