OF THE FAMILY BACILLAHIA. 131 



4th. Presence of distinct circulation. This was noticed many- 

 years ago by Gruthuisen. The account by JVIi-. Dahymple, given 

 in the above extract, agi'ees exactly \yI\\\ what I have seen in 

 several species. The currents are very distinct, so much so, in 

 fact, that they attracted my attention before I was aware that 

 they had been noticed by others. 



5th. Action of Iodine. — I cannot otherwise account for Mr. 

 Dalrymple's statement that iodine " in no instance produced in 

 the Closteria, the violet or blue color indicating starch," than by 

 supposing that the specimens he examined were not in the proper 

 state to exhibit it. Meyen expressly states, that it is " at certain 

 times, particularly in spring," that the starch may be detected. 



I am able, by conclusive experiments, to confirm Meyen's state- 

 ments as to the presence of starch in these bodies. In specimens 

 gathered in November, many of which I have still by me in a 

 living state, I find no difficulty in producing the blue or purple 

 color with tincture of iodine. Sometimes, however, the specimen 

 becomes so opaque by the action of this reagent, that the purple 

 color of the gi-anules can only be detected after crushing the 

 specimen by means of the compressor. The characteristic color 

 of iodide of starch is then shoivn most distinctbj. I have repeat- 

 edly ti-eated in this way the large species, C. trahecida (fig. 32, 

 PI. I,) as well as others, and have uniformly found that a portion 

 of the interior takes the blue or purple color. 



I cannot however consider the presence of starch in these 

 bodies as conclusive evidence that they are plants. Is it not pos- 

 sible that they are animals which feed, wholly or in part, on 

 amylaceous matter extracted from the aquatic plants among 

 which they live ? If so, the detection of starch in their stomachs 

 is not surprising. 



6th. Organs of motion and moving pajrillw. — These I have 

 not yet seen, but do not feel authorized to deny thek existence, 

 as I am well aware that my microscope,* although a very good 

 one, is probably inferior to the one used by Ehrenberg. It sliows 

 the lines on the scales of Podura as well as I have been able to 



* Made by Charles Chevalier, 130 Palais Royal, Paris. 



