Excerpt from Biological Studies At the present time, when the subject of mutations and species is discussed on every hand, and when every eye is keenly on the alert for new evidence among animals and plants, a sudden transformation of one known species into another known species is of interest. Such an incident has recently come under my observation; a Paramecium caudatum became P. aurelia, and remained so for about 45 generations, when it reverted to P. caudatum. Apart from the facts of the change, which in itself is of obvious importance from the standpoint of cellular biology, the essential question to consider is whether these two species are sufficiently well defined to justify their separation. If not, then the experiments and the changes indicated have less bearing on the general problem of mutation than upon the problems of cell physiology. If they are sufficiently distinct, then we have in this incident an interesting case of mutation. I personally believe that the slight differences that distinguish the two types of Paramecium are not of specific value, and hold that P. caudatum should be regarded as a mere variant of P. aurelia. Paramecium aurelia was the name given by Muller, in his general work on the Protozoa in 1773, to the ciliated organism which had been known as the "slipper animalcule." Several different species of Paramecium were created by Ehrenberg in 1838, and described in his work on the Infusionsthierchen. Most of these have been sifted out into other genera, and only three have remained, P. bursaria, P. aurelia, and P. caudatum. Paramecium caudatum and P. aurelia have been united into a single species by the majority of observers subsequent to Ehrenberg, on the ground that the differences upon which Ehrenberg had based his species were inadequate. The number of species was thus reduced to two, and the names used were P. aurelia and P. bursaria, the former having been given originally by Muller. About the Publisher Forgotten Books publishes
"synopsis" may belong to another edition of this title.
Shipping:
£ 37.46
From Germany to U.S.A.
Shipping:
FREE
From United Kingdom to U.S.A.
Seller: Forgotten Books, London, United Kingdom
Paperback. Condition: New. Print on Demand. This book delves into a groundbreaking experimental method applied to the design and implementation of water purification and sewage systems, revolutionizing the field in the late 19th and early 20th centuries. The author thoroughly examines how these techniques transformed the understanding and treatment of water and sewage, leading to significant advancements in public health and infrastructure development. Through meticulous research and comprehensive analysis, the book traces the evolution of these methods, exploring their impact on waterborne disease reduction and overall community well-being. This comprehensive work unveils the pivotal role of experimental approaches in shaping the modern water and sanitation landscape, showcasing their lasting legacy in safeguarding public health and improving quality of life. Forgotten Books publishes hundreds of thousands of rare and classic books. This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works. The digital edition of all books may be viewed on our website before purchase. print-on-demand item. Seller Inventory # 9781330455517_0
Quantity: Over 20 available
Seller: PBShop.store US, Wood Dale, IL, U.S.A.
PAP. Condition: New. New Book. Shipped from UK. Established seller since 2000. Seller Inventory # LW-9781330455517
Quantity: 15 available
Seller: PBShop.store UK, Fairford, GLOS, United Kingdom
PAP. Condition: New. New Book. Shipped from UK. Established seller since 2000. Seller Inventory # LW-9781330455517
Quantity: 15 available
Seller: Buchpark, Trebbin, Germany
Condition: Sehr gut. Zustand: Sehr gut - Gepflegter, sauberer Zustand. | Seiten: 346 | Sprache: Englisch | Produktart: Bücher. Seller Inventory # 25836311/2
Quantity: 1 available