88 N. H. COWDRY. 



active part in the formation of the sporangium wall, the com- 

 plicated spore capsules and capillitia, the hypothallus, the pig- 

 ment and lime deposits of the Myxomycetes. 



The occurrence of typical mitochondria in the active plas- 

 modia, crawling from place to place, as well as in all stages in 

 spore formation even to the fully mature spoie, surrounded as it 

 is with a thick restraining horny capsule must indicate one of two 

 things: either that the mitochondria are active in some of these 

 locations and passive in others or else that they take part in the 

 activities of the cell in all stages. The second supposition is 

 usually granted by workers on mitochondria in higher forms. It 

 is apparent, then, that this study of the Myxomycetes materially 

 supports the general supposition that the mitochondria are con- 

 cerned in some fundamental vital process common to all living 

 matter, perhaps with protoplasmic respiration and possibly 

 with growth. 



CONCLUSIONS. 



1. Mitochondria occur' in Arcyria, Badhamia, Ceratiomyxa, 

 Cribraria, Enteridium, Fuligo, Hemitrichia, Lycogala, Stemonitis 

 and probably in all other Myxomycetes. 



2. The mitochondria in Myxomycetes so far as can be as- 

 certained differ in no wise from those occurring in the majority of 

 plants and in all animals. 



3. The Myxomycetes resemble the lower animals much more 

 closely than they do the lower plants with respect to their mi- 

 tochondrial content. 



4. The Myxomycetes offer a unique opportunity in many ways 

 for the experimental study of mitochondria. 



BIBLIOGRAPHY. 

 Benda, C. 



'01 Die Mitochondriafarbung und andere Methoden zur Untersuchung der 



Zellsubstanzen. Verh. d. Anat. Gesell., pp. 155-174. 

 Chamberlain, C. J. 



'15 Methods in plant histology. Univ. of Chicago Press, 314 pp. 

 Champy, C. 

 'n Recherches sur 1'absorption intestinale et le role des mitochondries dans 



1'absorption et la secretion. Arch. d'Anat. micr., T. 13, pp. 55-170. 

 Coulter, J. W., C. R. Barnes and H. C. Cowles. 



'10 A Textbook of Botany. Vol. i, Morphology and Physiology. American 

 Book Co., New York, 484 pp. 



