In the article, theoretical and methodological views in biology of an outstanding poet and naturalist-botanist A. von Chamisso were reconstructed. Scarce and almost unknown textual evidence was exploited. It consisted of, among others, a story-fable Peter Schlemihls wundersame Geschichte. Chamisso’s views were close to those of A. von Humboldt and bore an empiristic character in the period when a general trend in the German biology was set by representatives of romantic philosophy of nature. This empiristic attitude made Chamisso an ardent supporter of the doctrine of the immutability of species and an opponent of all attempts to develop scientific investigations in a speculative way. According to Chamisso, empiricism also spoke against abiogenesis. In the historical aspect, he gave life a static form, depriving it of the dimension of time, as if he had described the picture of geological cross-section made across the outer layers of the earth’s crust. Nature – the subject of his study – appeared in his descriptions as a holistic, total object. Nature-wholeness portrayed in his depiction was gaining specificity, taking form on the ground of interaction of its parts. The man was treated by Chamisso as an important link in the natural economy, as an instrument, which is used by nature in its activity. Species – the subject of his interest as a taxonomist – was bestowed by Chamisso the real existence in nature. The validity of laws governing the animate world he spread equally to all its creation – from the simplest forms to the most complex. Chamisso was not a narrowly specialized empiricist, but a naturalist who was familiar with methodological reflection, he noticed and solved general theoretical problems, consistently obeying methodological rules. He created to a large extent coherent, but not very developed theoretical conception, which favourably stood out against a background of the 19th century German biology controlled by the romantic philosophy of nature. Taking such a theoretical and methodological position as described, Chamisso was the first to come out against to the highest degree speculative conception of metamorphosis (it should not be confused with the conception of metamorphosis of plants by J.W. Goethe), which was developed in the 20s and 40s of the 19th century by C.A. Agardh, F.T. Kützing and Ch.F. Hornschuch, whose foundation was their research mostly on lower organisms (algae, fungi, lichens and protozoans). Their conception in these three different versions was reconstructed in detail in the article. These versions have a common conviction that at this lower organizational level of the animate world there is abiogenesis: in the presence of the observer there are constant and two-way transitions between the plant and animal worlds. One plant species transforms into another, filamentous algae become elements of higher plants, unicellular organisms become multicellular (even the cormophytes) and these in turn break up into unicellular organisms. There is a terminological relic coming from that period - „zoospore”, denoting animal creature that a plant organism – alga – gave rise to. These three versions have also ordinary technical errors, as well as observational errors in the gradually recognized field of lower plants, still insufficient familiarity with microscope, lack of appropriate criticism towards collected alleged facts, but above all neglecting the basic rules of scientific investigation used in those times, or even common sense. Such an approach was encouraged by the activity of the representatives of German philosophy of nature. On the one hand, all three naturalists were aware how complex were the phenomena they wanted to investigate, what kind of difficulties they might encounter studying algae in algological investigations, because they wrote about it many times. On the other hand, they did not sufficiently control research procedures they applied, despite the fact they had at their disposal all the means to do it. At the same time, they resorted to pseudo-hypotheses lacking signs of probability. What is interesting is that the conception of metamorphosis found its ideological milieu on the continent, while it did not spread in Great Britain. On the contrary, it not only did not have its proponents here but also met with severe criticism, twenty years after polemic dissertation by Chamisso. Errors enumerated above concerning conception of metamorphosis were criticised in a particularly detailed manner by Chamisso in his dissertation. His criticism was developed on the factual, technical, theoretical and practical ground. Chamisso as a taxonomist-practicioner did not allow the thought that a species could be deprived of immutability, a feature extremely important exactly in the practice of a taxonomist. Species and genera must be characterized by immutability, wrote Chamissso, or else they do not exist at all. Two years later, Franz Paula Schrank expressed similar criticism, which was also included in the article. Reconstructed for the first time the conception of metamorphosis was based on original, little-known and coming from those times textual materials which were mentioned in the article.