132 Remarks on Glceocapsa. [Sess. 



The chlorophyll - graios in Glceocapsa are exceedingly 

 minute and irregular. They are perhaps representative of 

 the phylogenetic ancestors of the chloroplasts of higher 

 plants. No starch of the ordinary nature occurs in 

 Glceocapsa ; neither is any nvicleus to be found. The large 

 central bodies imbedded in the cytoplasm cannot be looked 

 upon as having close relationship to the nuclei of higher 

 plants ; they do not possess true chromatin, and any granu- 

 lations that may be observed are simply collections of 

 substances resembling glycogen. Whilst being quite aware 

 of the mischievous results produced by assuming identity 

 where only analogy exists, and of confounding analogy with 

 affinity, yet it may be suggested that the nuclear substance 

 in Glceocapsa is in a primitive form not at present perfectly 

 understood, — ancestor, perhaps, to the so - called scattered 

 nuclei, which occur undisputably in many Cyanophycese, in 

 flagellate infusoria, and in Rhizopoda. Whilst we must 

 avoid confounding analogy with affinity, yet we must also 

 distinguish that affinity may be great without the existence 

 of analogy. We become so inured to the usual form of 

 nuclei in general that we are apt not to recognise the 

 affinity of nuclear substance in an unorthodox condition. 



For mounting, the gathering of Glceocapsa is placed at one 

 end of a dish with water : a card is then placed over the 

 dish, leaving the end opposite to the gathering open to the 

 sunlight. After some hours the organisms will be found to 

 have left the mud and congregated towards the light. They 

 are then gathered with a pipette, and the process repeated 

 until they are obtained clean enough for the microscope. 

 The gathering freed from mud is allowed to settle in a tube, 

 as much water as possible decanted and replaced with the 

 following solution, which kills and fixes them. In the same 

 fluid they may be preserved, either in a tube, or mounted as 

 a slide for the microscope. The fluid preserves the colour 

 for many years. Acetate of copper, 0"5 gram; distilled 

 water, 100 cc. Mix, and add with stirring, at ordinary 

 temperature, gum acacia, 65 grams. When dissolved, add 

 pure glycerine, 55 cc. ; mercuric chloride, 2 grams. Filter 

 before use. 



