INTRODUCTION. 



Mr. Agardh then proceeds to detail the results of his 

 examination of Zygnemata, Ulva clathrata, Bryopsis Ar- 

 buscula, and other Algae, in all which he has noticed a 

 motion, apparently spontaneous, among the spores at the 

 period of germination. Similar observations on other Con- 

 fervoid Alga? have been made by many continental bota- 

 nists, particularly by Unger, an abstract of whose account 

 of Vaucheria clavata will be found in ' London's Mag. Nat. 

 Hist.'' vol. i. p. 305 ; by Meyen, Bory St. Vincent, Guillon, 

 Treviranus, Milne Edwards, and others who have commu- 

 nicated their discoveries in several memoirs inserted in the 

 ' Annales des Sciences NaturellesJ ' Encycl. MethodiqueJ 

 &c. ; in fact experiments have been so multiplied by inde- 

 pendent observers, and the result is so invariably the same, 

 that however difficult it may be to account for these ano- 

 malous motions, and however little they may accord with 

 our preconceived notions of the powers of vegetable life, it 

 is not possible to doubt the fact of their existence ; for we 

 cannot suppose that all these respectable witnesses have 

 been themselves deceived, or have wished to impose on 

 our credulity. The fact of the existence of motion being 

 granted, it will naturally be asked, how we are to account 

 for it ? Here we have vegetables producing spores which 

 exhibit a feature that we have been accustomed to regard 

 as one of the distinguishing characters of animal life. Are 

 these spores then animalcules ? This strange opinion is 

 not without its zealous supporters, who contend that an 

 actual metamorphosis takes place ; that the spore becomes 

 (how is not said) a perfect animalcule, which after enjoying 

 an animal existence for a time ceases to live animally, and, 

 reverting to its original nature, gives birth to a vegetable. 

 Thus, this seed was first vegetable, then animal, and then 

 again vegetable, and finally giving birth to animals to be 

 again transformed into vegetables, and so on. This opinion 



