146 THE BEGINNINGS OF LIFE. 



was not until 1840 that the development of ToruU 

 into Fungi was traced^. The multiplication of Bacteria^ 

 however, even more frequently takes place without 

 much tendency to the evolution of higher forms , and 

 when this does occur it is not quite so easily recog- 

 nizable as the development of Torulje, And yet in 

 those cases where the conditions are, as we must sup- 

 pose, favourable to such continuous modes of growth, 

 certain Bacteria may enlarge into Fi^rw-formSj these 

 into Leptotkrix.^ and the latter into larger and more 

 definite fungus- my celia, just as surely and just as 

 readily as the Torula corpuscle buds out into a growing 

 fungus-mycelium 2. 



The stages by which a Torula corpuscle develops 



^ It was believed by Kiitzing to be one of the unicellular Algae, and 

 the same view was afterwards adopted by Robin, in spite of the state- 

 ments of Turpin. The development of TorulcB at once into fungus- 

 mycelia, producing the mother of vinegar {Mycoderma aceta), contrasts 

 notably with the discontinuous mode of growth and perpetuation of 

 the Tonda form, which obtains in some forms of the vinous fermen- 

 tation. 



^ I have found the former development take place very readily in 

 certain infusions to which a minute fragment of cheese had been added, 

 and also in some solutions of ammonic tartrate and sodic phosphate. 

 (See Appendix D, Exps. xvii, xix, and lii). In other cases Vibrio-forms 

 may assume the Spirillum mode of growth, rather than that of Leptothrix, 

 before giving origin to a fungus-mycelium — as I have seen in an infusion 

 containing young twigs of the common elder. {Fig. 47 d.) Between 

 Leptothrix again and some of the colourless Oscillatorice there seems to be 

 no real ascertainable distinction. Moreover, all shades of increasing 

 greenness exist amongst the representatives of this latter family, which by 

 common consent is included amongst the Algae ; so that they constitute 

 transitions between the simplest Fvmgi and Alg^. 



