268 SCIENCE PROGRESS. 



is abundantly present, particularly in the resting sporangia. 

 The red colouring matter occurs in the form of oil drops, 

 and the colouring substance itself he thinks is hsematochrome 

 or, at least, something nearly related to it. Though this 

 might be considered indicative of the presence of chlorophyll, 

 it is to be remembered, as Lagerheim states, that this 

 substance (or something like it) occurs in Fungi which have 

 no chlorophyll, e.g., the Uredinece, Chrysochytrium, etc. 

 Dr. Lagerheim does not appear to have attempted to 

 reduce the haematochrome by experimental cultivation, and 

 thus disclose the presence or absence of chromatophores, as 

 Schmitz successfully did in the case of Hcematococcus, 

 Chroolepus, etc. One feels at first inclined to scout relation- 

 ships on physiological grounds such as this link would estab- 

 lish, but it is only fair to remember that after all many of 

 the differences between Protococcacece and Chytridiacece are 

 merely physiological. 



I must content myself with a mere chronicle of Dr. 

 Klebahn's paper (11) on genera of lower Algae. It is a 

 valuable one, but it hardly lends itself to a brief account 

 from its critical systematic character. This admirable 

 monograph (12) of the homocystal Nostocacece is the sequel 

 to the Revision des Nostocacdes HdUrocystdes by Bornet and 

 Flahault, which appeared a few years ago. It bears all the 

 external marks of supreme care in the text and beauty of 

 illustration that Bornet and Thuret have set example in, and, 

 when the book is put to the test of use, it fails in no way to 

 come up to the same high standard in its solid excellence of 

 workmanship. In order to be in a proper spirit and con- 

 dition of mind to appreciate this monograph, one must have 

 tried to name Oscillariece, and to arrange a collection of 

 them without it. The condition of the group was chaotic, 

 and it is now well ordered. M. Gomont has conscientiously 

 investigated the claims to stability of a vast number of types, 

 and has done this part of the work — the most valuable — in 

 a way indicated by the lists of species excludendcz and sftecies 

 inquirendce, almost as much as by the positive evidence of 

 the proper part of the monograph — its species and synonymy. 

 The division of the genera into sections is very judiciously 



