Untitled

Fig.		Page
118 .	Another diagram of two conjoined soap-bubbles	313
119 .	A froth of bubbles, shewing its outer or ãepidermalã layer	314
120 .	A tetrahedron, or tetrahedral system, shewing its centre of symmetry	317
121 .	A group of hexagonal cells (Bonanni)	319
122 ,ã3.	Artificial cellular tissues (Leduc)	320
124 .	Epidermis of Girardia (Goebel)	321
125 .	Soap-froth, and the same under compression (Rhumbler)	322
126 .	Epidermal cells of Elodea canadensis (Berthold)	322
127 .	Lithostrotion Martini (Nicholson)	325
128 .	Cyathophyllum hexagonum (Nicholson, after Zittel)	325
129 .	Arachnophyllum pentagonum (Nicholson)	326
130 .	Heliolites (Woods)	326
131 .	Confluent septa in Thamnastraea and Comoseris (Nicholson, after Zittel)	327
132 .	Geometrical construction of a beeãs cell	330
133 .	Stellate cells in the pith of a rush; diagrammatic	335
134 .	Diagram of soap-films formed in a cubical wire skeleton (Plateau)	337
135 .	Polar furrows in systems of four soap-bubbles (Robert)	341
136 ã8.	Diagrams illustrating the division of a cube by partitions of minimal area	347ã50
139 .	Cells from hairs of Sphacelaria (Berthold)	351
140 .	The bisection of an isosceles triangle by minimal partitions	353
141 .	The similar partitioning of spheroidal and conical cells	353
142 .	S-shaped partitions from cells of algae and mosses (Reinke and others)	355
143 .	Diagrammatic explanation of the S-shaped partitions	356
144 .	Development of Erythrotrichia (Berthold)	359
145 .	Periclinal, anticlinal and radial partitioning of a quadrant	359
146 .	Construction for the minimal partitioning of a quadrant	361
147 .	Another diagram of anticlinal and periclinal partitions	362
148 .	Mode of segmentation of an artificially flattened frogãs egg (Roux)	363
149 .	The bisection, by minimal partitions, of a prism of small angle	364