NOTES AND MEMORANDA. 297 



of the branches on the stem of Confervaceae." The author 

 adds a hypothetical " genealogical tree" of the Chlorophyll- 

 phycere, with some brief remarks on the Cohn-Sachsian 

 principles of classification, adding that " a more particular 

 account of the motives of this attempt it is his intention to 

 publish on another occasion," a promise which algologists will 

 be anxious he may early fulfil. 



The author concludes his extensive and valuable memoir 

 with complete and thorough descriptions of the species belong- 

 ing to his new genus Pithophora, to which are appended six 

 plates (uncoloured) pourtraying the characters of their habit 

 and growth, so that the whole amounts to an exhaustive 

 Monograph of the new Order. 



On some Changes which Red blood- Corpuscles undergo in Ex- 

 travasations. By Professor A. Boettcher, in Dorpat.^ — Refer- 

 ring to the observations of Dr. Max Knies on certain peculiar 

 nucleated forms of blood-corpuscles found in blood twenty-four 

 to seventy-two hours after having been injected into the ante- 

 rior chamber of the eye of rabbit, Professor Boettcher draws 

 attention in this paper — of which only the first part will be 

 here reported on — to observations of his own on a similar 

 subject in ' Virchow's Archiv,' vols. 36 and 39, when he found 

 that treating red blood-corpuscles with blood-serum or 

 humour aqueus nucleated blood-corpuscles are to be met with. 



Professor Boettcher then describes another method, by 

 means of which the nuclei of red blood-corpuscles of man 

 and several mammalian animals may be readily demonstrated. 

 Twenty-four to forty-eight hours after injection of defi- 

 brinated blood into the anterior chamber of the eye of 

 rabbit, there were no distinctly nucleated red blood-corpus- 

 cles to be seen yet. But leaving this blood, viz., withdrawn 

 after twenty-four hours, to stand in humour aqueus in a small 

 glass for another twenty-four hours, the most splendid and 

 diversely nucleated red blood-corpuscles could be demon- 

 strated. The nucleus appears of different sizes, generally it 

 is very sharply outlined ; the larger nuclei are granular, the 

 smaller pale. There are also few nuclei to be met with 

 which had escaped their red corpuscles. There exists a dif- 

 ference between the red blood-corpuscles of man and rabbit 

 on the one hand, and those of cat on the other, those of the 

 former possessing a granular, those of the latter a pale 

 nucleus, which at the same time can be recognised only 

 under a higher power. Besides this the clear nucleus of 

 many red blood-corpuscles of cat contains a nucleolus. If 



' Virchow's ' Archiv,' vol. 69, part ii, p. 295. 



