LIST OF ILLUSTEATIONS 



FIG. 



104, 5. Diagrams of the partition -wall between two soap-biibbles 



106. Diagram of a partition in a conical cell 



107. Chains of cells in Nostoc, Anabaena and other low algae 



108. Diagram of a symmetrically divided soap-bubble ... 



109. Arrangement of partitions in dividing spores of Pellia (Campbell) 



110. Cells of Dictyota (Reinke) 



111. 2. Terminal and other cells of Chara, and young antheridium of do 



113. Diagram of cell-walls and partitions under various conditions of 



tension ......... 



114, 5. The partition-sui'faces of three interconnected bubbles 



116. Diagram of four interconnected cells or bubbles 



117. Varioiis configurations of four cells in a frog's egg (Rauber) 



1 18. Another diagram of two conjoined soap-bubbles 



119. A froth of bubbles, shewing its outer or "epidermal" layer 



120. A tetrahedron, or tetrahedral system, shewing its centre of symmetry 



121. A group of hexagonal cells (Bonanni) .... 



122. 3. Artificial cellular tissues (Leduc) ..... 



124. Epidermis of Oirardia (Goebel) ..... 



125. Soap-fioth, and the same under compression (Rhumbler) 



126. Epidermal cells of Elodea canadensis (Berthnld) 



127. Lithostrotion Martini (Nicholson) ..... 



128. Cyathopkylbtm hexagomim (Nicholson, after Zittel) . 



129. Arachnophyllum pentagonum (Nicholson) .... 



130. Hdiolites (Woods) 



131. Confluent septa in Thamnastraea and Comoseris (Nicholson, after 



Zittel) ... 



132. Geometrical construction of a bee's cell .... 



133. Stellate cells in the pith of a rush ; diagrammatic 



134. Diagram of soap-films formed in a cubical wire skeleton (Plateau) 



135. Polar furrows in systems of four soap-bubbles (Robert) 

 136-8. Diagrams illustrating the division of a cube by partitions of minimal 



area ........... 



139. Cells from hairs of Sphacelaria (Berthold) .... 



140. The bisection of an isosceles triangle by minimal partitions . \ 



141. The similar partitioning of spheroidal and conical cells . 



142. S-shaped partitions from cells of algae and mosses (Reinke and others) 



143. Diagrammatic explanation of the S-shaped partitions 



144. Development of Erythrotrichia (Berthold) 



145. Periclinal, anticlinal and radial partitioning of a quadrant 



146. Construction for the minimal partitioning of a quadrant 



147. Another diagram of anticlinal and perichnal partitions . 



148. Mode of segmentation of an artificially flattened frog's egg 



(Roux) ......... 



149. The bisection, by minimal partitions, of a prism of small angle 



150. Comparative diagram of the various modes of bisection of a prismatic 



sector ......... 



151. Diagram of the further growth of the two halves of a quadrantal cell 



152. Diagram of the origin of an epidermic layer of cells 



153. A discoidal cell dividing into octants .... 



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