244 PROFESSOR E. RAY LANKESTER, 



me seven years ago in this Journal (1874, vol. xiv, p, 400)^ 

 I found that when a piece of colourless Spongilla is dipped 

 into sulphuric acid, it immediately assumes an intense green 

 colour. It is well known that sulphuric acid has a similar 

 action upon some vegetable cells, which are remarkable for 

 the suppression of what may be considered their normal 

 green pigment. The saprophyte, Neottia, is devoid of 

 chlorophyll, but when treated with sulphuric acid certain 

 substances in the protoplasm of its cells appear to develop 

 rapidly a green-coloured body resembling (at any rate in 

 colour) the green pigment of other plants. 



The destructive nature of the reagent employed has pre- 

 vented me from ascertaiTiing, by observing the action under 

 the microscope, whether the green colour thus developed 

 in colourless cells of Spongilla arises from a change of the 

 angular corpuscles. It can hardly be doubted that this is 

 the case. 



It does not seem possible to hold the view that the 

 colourless angular corpuscles are colourless parasitic Algae 

 ready to develop into green varieties when exposed to sun- 

 light ! They have even less of the form and structure of 

 independent organisms than have the green corpuscles of 

 the verdant varieties of Spongilla. 



Dr. Brandfs observations and conclusions with reference 

 to the chlorophyll-corpuscles of Spongilla. — .Dr. Karl Brandt 

 has recently published certain observations with reference 

 to the green-coloured corpuscles of both Spongilla and 

 Hydra, which lead him to the conclusion that these bodies 

 are not " chlorophyll-corpuscles " similar in nature to the 

 " chlorophyll bodies " of plants, but parasitic or " symbio- 

 tic " unicellular Algae. 



It is to be hoped that Dr. Brandt will soon publish his 

 observations more in detail, together with illustrative 

 figures. In the memoir which he has already issued Dr. 

 Brandt makes a series of statements, which are applied by 

 him both to the chlorophyll-corpuscles of Spongilla and to 

 those of Hydra. 



He observes : 



(1) That he studied the chlorophyll-corpuscles when 

 isolated from the tissues of the animal by means of pressure. 



(2) That the corpuscles thus isolated are not equally and 

 completely green, but possess besides the green-coloured 

 substance always some portion of hyaline protoplasm. 



(3) In the hyaline colourless part of the green bodies a 

 cell nucleus could in all cases be detected with absolute 

 certainty by treatment with hsematoxylin. Sometimes more 



