142 [Assembly 



of bovistagigantea (a fungus) have been produced at the rate of 

 more than Q6 millions in a miiiute^ and Ward noticed a similar 

 occurrence in phallusirapudicus. 



For interesting information on these points vide Schleiden's 

 Phytogenesis (origin of vegetable growth), and Mohl on cells, 

 Maezeli also. 



The cells often contain crystals of various figures; the crystals 

 in rhubarb cause the roughness to the taste. 



POLLEN— (From Balfour). 

 The length of time during which it retains its vitality is very 

 different in plants. Gaertner says that in some species of Nico- 

 tiana (the tobacco family) the pollen retains vitality only forty- 

 eight hours, that of Datura (of the potato family) the same, of 

 Candollea one year, of Datepalm m^re than one year, aid of some 

 palms, and of the Chamaerops humilis (of the palm family) more 

 than eighteen years. 



Nearly all botanists agree in the existence of tubes proceeding 

 from the pollen, instrumental in reaching the ovules of plants. 

 As to hybrids, the pollen of one species will fertilize the ovules 

 of another, producing plants strictly composed of the properties 

 of both plants, as mules are of the horse and ass. Some very 

 analogous plants, however, will not mix, such as apple with pear, 

 gooseberry with currant, ra^pberiy with strawberry. Hybrids 

 do not [)erpetuate themselves by seed, and if not absolutely bar- 

 ren at first, they usually become so in the second or third gene- 

 ration. Hybrids may be fertilized by the pollen from one of their 

 parents, and in that case the offspring takes the charact* r of that 

 parent. Hybrids are abundantly pioduced to obtain very choice 

 flowers and fruits, and the plants are propogated by cuttings. In 

 this way beautiful Roses, Azaleas, Rhododendrons, Pansies, Cac- 

 tuses, Pf^largoniums, Fuchsias, Calceolarias, Narcissuses, &c , are 

 produced. The size and color of the flowers are improved, ten- 

 der plants are rendered hardy, and the flavor of fruits height- 

 ened. 



