158 BACTERIA. 



(k) Reproduction. — This in living things is either asexual 

 or sexual. The former is called agamoge?iesis {a — without, 

 yajxoQ — marriage, ytviaiQ — reproduction). The latter, gauwgenesis. 

 Only the asexual or agamogenetic is known in connection with 

 those low forms of living things. The particular method encoun- 

 tered here is division or technically, fission (findo — I split). 

 Certain divisions of the Bacterium undergo transverse division. 

 A cytode is divided into two by an ingrowth of its wall, and the 

 cytodes thus formed last a longer time, and can resist injurious 

 agencies more effectually than their fellows. By such division a 

 Bacterium becomes two Bacteria. Bacillus also produces spores — 

 e.g,^ rounded structures that are thrown off from the parent and 

 developed into a new being. 



(/) Development. — Nothing can be said here, as the new 

 individual is of the same nature as the parent. 



(;;/) Classification. — Cohn classifies the Bacteria according to 

 their form into SpJicBrohadcria (globular cells), Microhac- 

 teria (minute, rod-like cells, Bacteria proper), Desniobacteria 

 (larger rod-like or filiform cells, Filobacteria), and Spirohacteria 

 (twisted or spiral cells). The student should rigidly adhere to 

 order in this. For our convenience w^e divide everything in the 

 universe as mineral, animal and vegetable. We regard each 

 kingdom as divided into sub-kingdoms. These again, contain 

 classes. Each class is made up of orders. An order has genera 

 (genus — kind). A genus consists of species. Hence in classifying 

 Bacteria, w^e say its food is inorganic, therefore it belongs to the 

 kingdom Vegdahilia. It is a flowerless plant, without stamens 

 and carpels ; therefore, it belongs to the sub-kingdom Cryptogamia 

 (KpvTTTog — hidden, yafiog — marriage). There is no distinction of 

 axis and appendages, as in the stem and leaves of a tree ; there- 

 fore, it is of the group Thallophyta (9a\\og--3. sprout, i)vrov — a 

 plant). It is without green colouring matter, chlorophyll ; there- 

 fore of the class Fungi. Gamogenesis unknown, fission the only 

 form of agamogenesis ; therefore, of the order Schizomycetes 

 ((7X1^0) — I split, \xvKoc, — fungus). Genus, Bacterium^ Vibrio^ or 

 Baci/lus, etc. 



