40 



CASSELL'S POPULAE GAEDENING. 



CarlMendel, brigM crimson. 

 Cloth of gold, yellow. 

 Crimson Gem, crimson. 

 George Thoujpsou, pale yel- 

 low. 



John WyattjCrimson-scarlet 



Bedding Bahlias. 



Marguerite Bruant, white. 

 Rising Sun, scarlet. 

 Eoyal Purple, purple. 

 Yellow Pet, pare i ellow. 

 Zelinda, crimson-purple. 



Bouquet or Pompon Dahlias. 



Comtesse von Sternberg, 

 yellow and white. 



Coquette, orange. 



Dora, primrose and white. 



E. F. Jungker, amber. 



Favourite, dark maroon- 

 Fireball, orange-red. 



Gazelle, yellow, edged ma- 

 genta. 



Gem, rich scarlet. 



German Favourite, crimson- 

 Jake. 



Grass an Wien, shaded buff. 

 Hedwig Polwig, orange- 



scai'let. 

 Isabel, bright orange-scarlet. 



Lady Blanche, pure white. 

 Little Diichess, white, edged 



crimson. 

 Louis Eodani, deep shaded 



lilac. 

 Mabel, bright lilac. 

 Nympli, yellow, tipped with 



red. 



Prince of Lilliputians, very 

 dark maroon. 



Princess Sophie Sopieha, 

 shade 1 la'- e. 



Titania, yellow, tipped with 

 bronze. 



Willie Im Nitsche, red, tip- 

 ped with white. 



SingU Dahlias. 



(The following are we'l-known and serviceable varieties, 

 but many new ones are being raised every year.) 



Mrs. Bowman, purplish 

 magenta. 



Alba, pure white. 

 Amos Perry, shining ma- 

 roon. 



Coccinea, bright scarlet. 

 Dorothy, white and peach. 

 Firefly, pale crimson. 

 Harlequin, rose and purple. 

 Mauve Queen, pale lilac. 

 Miss Mary Anderson, crim- 

 son scarlet. 



Mr. Kennett, striped. 

 Norah, bright pink. 

 Paragon, rich maroon and 

 purple. 



Eosamond, bright rosy pink. 

 >^unset, brigi't crimson. 

 Yellow Dwarf, yellow. 

 Yellow Queen, deep yellow. 



The rich semi-donMe C >ctus Dahlia, D. Juarezii, should 

 also be included in this collection. 



to the cultivator, leaving those who desire to pursue 

 the suhject further to consult some ot the more re- 

 cently puhlished text-books. 



Cells, their Structure and OflB.ce. — For our 



present purpose it suffices to say that the cell exists 

 in various forms and phases, but that in its perfect 

 condition it consists of an outer bag of membrane 

 called the "cell- wall," and of certain contents, 

 of which the most important is the substance known 

 as " protoplasm," The other contents — the cell-sap, 

 the vacuoles, the nucleus, Sec. — cannot be advan- 

 tageously treated of in this place. The cell- wall is, 

 as has been said, a bag of membrane, for the most 

 part closed, so that one cell is isolated from its 



THE LIFE-HISTORY OF PLANTS. 



By Dr. Maxwell T. Masters. F.E.S, 



NUTRITION. 



WE have now passed in review the principal re- 

 serve organs in which food is stored for the 

 use of the plant when growth begins. In a general 

 way we have indicated the nature of the change from 

 the insoluble reserve-material, useless as such, to the 

 soluble food capable of being utilised in the growth 

 of the plant. We are, therefore, now in a position 

 to follow up the life-history of the plant, to see in 

 what growth consists, what circumstances promote 

 it, what the plant feeds on, how it obtains its food, 

 and what it does with it. Growth consists essen- 

 tially iii the formation of new " tissue " or sub- 

 stance, and this is effected at the growing points 

 before mentioned. This new tissue or substance is 

 composed of aggregates of minute bladders called 

 " cells " (Fig. 31), generally more or less globular, but 

 subject to great variations in form. The study of 

 cells demands the exercise of the keenest powers of 

 the trained botanist and chemist. In this place it is 

 proposed only to deal with a few leading facts and 

 phenomena concerning them of special importance 



Fig. 31.— Aggregation of Cells constituting Cellular Tissue, 

 shown cut across. 



neighbour, but not so much so as to prevent all pas- 

 sage of some of the contents of one cell into the 

 cavity of another. That passage may be effected 

 either by endosmosis, which is the most ordinary 

 method, or by the direct passage of the protoplasm 

 of one cell into another. 



Endosmosis is the term applied to that process 

 by means of which a thin fluid, say water, passes 

 through an intervening membrane, even though 

 there be no visible pores in it, to mix with a thicker 

 fluid, say syrup. This process may easily be exem- 

 pli tied by stretching a piece of bladder over the broad 

 end of a funnel (a, Fig. 32), inverting it and pouring 

 into it through the narrow tube (b) some sugar and 

 water. This done, the funnel may be placed, with 

 the broad end downwards, in a vessel of water as in 

 the figure, the tube of the funnel being secured by 

 means of a ring and screw to a stand. After a 

 short time, varying according to temperatm^e and 

 the strength of the syrup, it will be found that the 

 water from ihe vessel will pass through the bladder, 

 causing it to be distended, and the fluid in the 

 funnel, becoming more abundant and more and 

 more diluted, rises in the tube. It is, therefore, by 



