Lens

Seitenzahl:

222

Gewicht:

331 g

Erschienen bei:

Cambridge Scholars Publishing

Kurzbeschreibung

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: we have, in the very marked difference between the results of conjugation of Desmids and Diatoms, one of the strongest proofs of their complete dissimilarity; for the sporangium of the latter which is generally of much larger size than the parent frustules, serves to restore again the cycle by commencing self-division in a large form, when, by the act long repeated, the frustules had become very small. No doubt many do go on until myriads of small forms appear, thus self-dividing until finally they die out, without any renewal by conjugation. To finish our remarks on figure 85, (reproduced from M. Gros), (t) and (f) are referred to as two forms of Diatoms which may arise from transformed Euglence; these are probably Navicula, one in front, the other in side view; but what Navicula this representation is too imperfect for decision, (d) and (d') are called Chlamidomonas, (sic) giving origin to Diatoms. Dr. Gros' account of this transformation is too absurd to be worth repeating here, (d) Is very much like a small Amphora possibly a Cocconema, self-dividing, and ((/') may be dorsal aspect of a Cocconema; any resemblance to Chlamidomonas, or any reason to infer development from this is most fanciful. In view, then, of this entirely insufficient evidence, how can Dr. Bastian say, p. 420, that " the actual transformation has been witnessed by independent observers, whereby algoid or Euglenean corpuscles are bodily converted into Diatoms or Desmids" ? We have dwelt thus long and particularly on one special portion of the book, because upon this we felt best qualified to act the part of an honest critic. We have no "constitutional objections " or " religious scruples " about accepting anything which can be proved, either as to Arehebiosis or Heterogenesis, but we want no fancy pictur...

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Mehr von:  State Microscopical Society of Illinois, Cambridge Scholars Publishing