ADAPTATION^ AND INHEKITANCE — KAMMEEER. 423 



resistance against bacterial or other poisons (chicken, mouse, rabbit, 

 man). 



As is well known, many of the lower plants and animals multiply 

 by simple fission, and the resulting elements attain in course of time 

 the form and size of the parent. Or they may multiply by having a 

 bud developing on any part of the body, wliich in time assumes the 

 form of the entire parent or animal upon wliich it is developed, 

 usually separating from the parent to lead an independent existence. 

 Multiplication of this type by fission or budding may occasionally 

 occur in many liigher animals or plants, especially so when they have 

 been injured by mechanical separation, and each part possesses the 

 power to regenerate the lost portion. In tliis asexual reproduction 

 we reahze best that the offspring resembles the parent, or in other 

 words that the pecuHarities of the parent have been transmitted to 

 the offspring. We even accept tliis when the parents have acquired 

 new characters in their incUvidual existence, for why should the 

 pieces possess different characters than the material from wliich 

 they sprang unchanged ? 



Still, it is not necessarily true that newly acquired characters must 

 appear in the progeny. Metalnikow fed Protozoa with grains of 

 carmine and India ink. Although they devoured those indigestible 

 particles at first, the}^ nevertheless gradually learned to push them aside 

 and to avoid them. But as soon as fission had rendered the organ- 

 ism into two daughter cells, these seemed to be ignorant of the indi- 

 gestibihty of the carmine or India ink, for they devoured both greedily. 



Leaving out of consideration the constituents or peculiarities of 

 those elementary building blocks of life, the so-called cells, this smiple 

 ex])eriment, recently challenged, it is true, by Schafer, demonstrates the 

 following fundamental facts: That even in reproduction by simple fis- 

 sion gernij)lasm, which contains the material for the next generation, 

 must be distinguished from the purely individual soma|)lasm, which 

 perishes with the single example. The bodily peculiarities, be they 

 young or old, must be imj)ressed upon the germplasm of the next 

 generation in order that they may not become lost but may continue. 

 With this, then, we state that asexual reproduction does not differ 

 as far as their principles is concerned, from sexual re})roduction. If 

 we find transmission of acquii'ed characters in organisms which 

 multi])ly ascxually, we may therefore attribute to them the same 

 significance as in those which reproduce by the sexual methods. 



Jennings found curiously misshaped examples of a Protozoan 

 (the slipper animalcula Paramaecium, fig. 1),* in densely populated 

 cultures, where there was a lack of food. 



Jennings transj)lante(l one of these from the poor medium into one 

 presenting favorable conditions and followed the progeny through 22 



• The figures are reproduced on plates 1 to 8. 



