30b THE MICROSCOPE. 



but, of the last-mentioned, it should be stated that they are 

 almost solely found in Fungi, which have really no other 

 reproductive organ. The spores present many points of dif- 

 ference, both in number and character, in different genera 

 and species, and for this reason are most interesting micro- 

 scopic objects. We would direct the reader's attention to 

 an interesting and valuable paper, from the pen of Dr. 

 Lauder Lindsay, in the Linnean Soc. Trans., vol. xxv. 

 p. 493, " On the Lichens of ISTew Zealand" (the country 

 par excellence of certain Lichens). The paper is very 

 beautifully illustrated, showing chiefly the minute or 

 microscopic anatomy of the reproductive organs of the 

 species examined, especially the character of their spores 

 and spermatia. 



A vertical section of Parmelia stellata is given in 

 Plate I. No. 26 : it belongs to an extensive genus of 

 Gymnocarpous open-fruited Lichens, found growing upon 

 trees, palings, stones, walls, &c. The emission of the ripe 

 spores of the Lichens is a curious process, and not unlike 

 that which is seen to take place in some of the Fungi, as 

 in Pezizce, Splicerice, &c. If a portion of the thallus be 

 moistened and placed in a common phial, with the apothecia 

 turned toward one side, in a few hours the opposite sur- 

 face of the glass will be found covered with patches of 

 spores, easily perceptible by their colour ; or if placed on 

 a moistened surface, and one of the usual glass slips laid 

 over it, the latter will be covered in a short time. As to 

 the powers of dissemination of these lowly organized 

 plants, Dr. Hicks's observations lead to the conclusion 

 that the gonidia of Lichens have greater powers in this 

 direction than has been generally supposed. He found 

 by placing a clean sheet of glass in the open air during a 

 fall of snow, and receiving the melting water in a tube or 

 bottle, that he obtained large quantities of what has been 

 looked upon as a " unicellular plant, commonly called 

 ' ChlorococcusJ the cells of which may remain in a dor- 

 mant condition for a long time during cold weather, 

 but upon the return of warmth and moisture they begin 

 to increase by a process of subdivision, into two, four, 

 or eight portions, which soon assume a rounded form and 

 burst the parent cell- wall open; these secondary cells 



