xviii EXPLANATION OF PLATES 



PLATE XIV. (Facing p. 664) 



PURE-CULTIVATIONS OF BACTERIA 



Fig. 1. In the depth of Nutrient Gelatine. A pure-cultivation of Koch's 

 comma-bacillus (Spirillum cholera Asiatics) showing in the track of the 

 needle a funnel-shaped area of liquefaction enclosing an air-bubble, and a 

 white thread. Similar appearances are produced in cultivations of the comma- 

 bacillus of Metchnikoff. 



Fig. 2. On the surface of Nutrient Gelatine. A pure-cultivation of Bacillus 

 typhosus on the surface of obliquely solidified nutrient gelatine. 



Fig. 3. On the surface of Nutrient Agar-agar. Pure-cultivation of Bacillus 

 indicus on the surface of obliquely solidified nutrient agar-agar. The growth 

 has the colour of red sealing-wax, and a peculiar crinkled appearance. After 

 some days it loses its bright colour and becomes purplish, like an old cultiva- 

 tion of Micrococcus prodigiosus. 



Fig. 4. On the surface of Nutrient Agar-agar. A pure -cultivation obtained 

 from an abscess (Staphylococcus pyogenes aureus). 



Fig. 5. On the surface of Nutrient Agar-agar. A pure-cultivation obtained 

 from green pus (Bacillus pyocyaneus). The growth forms a whitish, transparent 

 layer, composed of slender bacilli, and the green pigment is diffused throughout 

 the nutrient jelly. The growth appears green by transmitted light, owing to 

 the colour of the jelly behind it. 



Fig. 6. On the surface of Potato. A pure-cultivation of the bacillus of 

 glanders on the surface of sterilised potato. 



PLATE XV. (Facing p. 756) 



COMPLETE LIFE-HISTORIES OF TWO SAPROPHYTES 



(Drawn from nature by Dr. Dallinger) 



PLATE XVI. (Facing p. 763) 



The various stages of the development of the nucleus in two saprophytic 

 organisms, as studied with recent homogeneous and apochromatic objectives 

 both in the several stages of fission and genetic fusion, indicating karyoki- 

 nesis, and proving, as established in detail by the text, that all the steps in 

 the cyclic changes of these unicellular forms are initiated in the nucleus before 

 being participated in by the whole body of the organism. (Drawn from nature 

 by Dr. Dallinger.) 



PLATE XVII. (Facing p. 792) 



ROTIFERS 



Fig. 1. Floscularia campanulata. 

 Fig. 2. Steplwnoceros EichJiornii 

 Fig. 3. Melicerta ringens. 

 Fig. 4. Pedalion mirum (side view). 

 Fig. 5. P. mirum (dorsal view, showing muscles). 

 Fig. 6. Copeus cerbems (side view). 



Fig. 7. Philodina aculeata (side view, corona expanded). 

 Fig. 8. Male of Pedalion mirum. 



All these figures, save fig. 2, are reduced to scale from the beautiful plates 

 in Hudvson and Goss's Rotifera. 



PLATE XVIII. (Facing p. 797) 



FORAMINIFERA 



Fig. 1. Miliolina seminulum (a and b, lateral aspects). 



Fig. 2. Alveolina Boscii (a, lateral aspect ; 6, longitudinal section). 



