INVEBTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. * 471 



At first it was supposed to confirm the view of Mr. Gosse that 

 Acineta is a stage in the life-history of the Vorticellinas, but on 

 closer examination it was seen that the stems of the Acineti^ were 

 attached to the side of a stem of the Epistylis instead of being a 

 continuation of the latter. The Acinetos were also foimd attached in 

 the same way to a group of Carchesium polypinum, and it was seen 

 that when the latter were disturbed and made to contract, the Acinetce 

 remained rigid, showing that their stems formed no part of the con- 

 tractile stems of the Carchesium. 



Eozoon Canadense.* — Principal Dawson contributes a further 

 paper on this subject, in which he criticizes in somewhat emphatic 

 terms Professor Mobius's book on Eozoon, and more especially his 

 recent reply,| which is, Dr. Dawson considers, written in a manner 

 which " relieves him from any obligation to be reticent as to the 

 Professor's errors and omissions." In reply to Professor Mobius's 

 suggestion that he should be supplied with more and better specimens, 

 the author says that " if he will take the trouble to visit Canada and 

 inspect my collections, he shall have every ojiportunity to do so." 



Dr. Dawson also criticizes at length a contribution by Dr. Otto 

 Hahn % to the literature of Eozoon, which he appears to have taken 

 for a serious instead of an ironical production ! Dr. Hahn (who in 

 reality is a supporter of the mineral origin of Eozoon) is described by 

 Dr. Dawson as now regarding it " as a vegetable production, or rather 

 as a series of such productions, the laminaa being petrified fronds 

 of a seaweed, and the canal systems finer algfe of several genera and 

 species. Not content with this, he describes as plants other forms 

 found in granite, gneiss, basalt, and even meteoric iron, and others 

 found included in the substance of crystals of arragonite, corundum, 

 and beryl. All these are supposed to be algfe of new species, and 

 science is enriched by great numbers of generic and specific names to 

 designate them, while they are illustrated by thirty plates rei)resent- 

 ing the quaint and grotesque forms of these objects, many of which 

 are obviously such as we have been in the habit of regarding as mere 

 dendritic crystallizations. Cavities, or impurities included in crystals." 



Dr. Dawson cites translated extracts from Hahn's work, and 

 adds that it " seems scarcely necessary to criticize the above 

 statements, as it is probable that very few naturalists will bo 

 disposed to accept the supposed plants as veritable species. It may 

 be observed, however, that in regarding the thick plates of serpentine — 

 interrupted, attached to each other at intervals, penetrated by pillars 

 of calcitc, and becoming acervulinc upward — as fossil algfc. Dr. Hahn 

 disregards all vegetable analogies ; while in supposing tliat the calcite 

 is a filling, and that the delicuto fillings of canals contained in it arc 

 fine thread-liko algfc, he equally asserts what is improbable. Further, 

 no vegetable structure or remains of carbonaceous matter have been 

 discovered in the serpentine. Had he discovered these supposed 

 vegetable forms in the graphite of the Laurontian, this would have 

 been far more credible." 



* ' Cftiuul. Nut.,' ix. (1879) p. 228. t This Journal, ii. (1879) p. 902. 



X ' Dif Ui/cllr ' (Svo, Tubingen, 1879). 



