PLANT DEVELOPMENT. 23 ' 



by the. name Parthenogenesis (Gr. parthenos, virgin, genesis, parent- 

 age), or Virgin Parentage. There is no reason why the little Proto- 

 coccus mother should be denied the distinction of womanhood merely 

 because she remains forever in the embryonic condition. This mode 

 is also called Oemmiparous (Gr. gemma, bud or bulb, pario, I bring 

 forth) ; the daughter-cells being compared to the gems (stem-bulbs) of 

 the Lily and Onion. This is not an accurate term, however ; it is best 

 to avoid loose definitions, and to learn 



41. The Difference between Reproduction [Generation) and Multipli- 

 cation. — The Lily and Onion multiply by bulbs (subterranean) and 

 gems (stem-bulbs) ; the Rose multiplies by stolons (shoots from the 

 root). We say, therefore, of the Lily that it is bulbiferous and gem- 

 miferous — bulb-bearing and gem-bearing ; of the Eose, that it is 

 stoloniferous. These bulbs, gems, and stolons are a part of the old 

 plant (old generation), like a leaf or twig ; 

 we plant them, and each grows up into a 

 perfect individual ; the race is thus in- 

 creased by Multiplication. The new gen- 

 eration, however, is always produced by the 

 floral organs, and in a mother-cell. These 

 organs ai'e a part of the old plant (old gen- 

 eration), like the leaf, twig, bulb, etc. ; but 

 their offspring is the new generation, the 

 embryo, which becomes a perfect individ- 

 ual ; the race is thus increased by Repro- 

 duction or Generation. 

 _ 42. One of the most beautiful protophytes j,,^ i2.-ybfeo^ ^loM^r; a 

 IS the FottJoa; (?iOOator, or JKevolvmg Globe colooy of ciliated zoospores; 

 (Pig. 12). It consists of a colony of one- greatly magnified. The eight 

 celled plants, in a transparent envelope or Sgingtto o'JgouTa':"'"-""' 

 common cell-wall ; each individual is a cili- 

 ated active zoospore, flask-shaped, with two cilise at its pointed end ; 

 the plants so arranged that their ciliae protrude through the common 

 envelope, giving the globe a hairy appearance. The Volvox has a 

 constant rolling motion. It is common in ponds, and is about -y'j of 

 an inch in diameter. Among these simplest types are the Microbes 

 (Gr. m,ikros, small, bios, life), called Bacteria by scientists (Latinized 

 bacterium from Gr. bakterion, rod). They are rod-like, rigid; repro- 

 ducing by transverse fission, — cutting the cell into two equal parts, 

 each part becoming a perfect individual. They are the smallest, the 

 most beautiful, yet most formidable of living creatures : being the 

 cause of putrefaction and of all loathsome and deadly diseases. They 

 are omnipresent, active, nearly indestructible; in air, earth, water, hot 

 or cold ; in filth ; in old straw, shucks, wool, feathers, etc., in bedding ; 

 in wall-paper, carpets, rags, soiled clothing ; in privy-vaults, sewers, 

 swamps. Cleanliness is the only safegiiard against them. 



43. Next come the, Diatoms and Desmids, the most in- 

 teresting children of the microscopic world. They exist in 

 rust-colored, jelly-like masses, or in slender, rigid filaments, 

 or otherwise variously arranged. Sometimes they are soli- 



