ON THE NATURE OF MITOCHONDRIA 225 
ADDENDUM 
After this paper was submitted for publication, my attention was 
called to a work by Portier (18) entitled, ‘‘Les Symbiotes,” and to 
criticisms of Portier’s book by Regaud (719) and Guilliermond (’19). 
Unfortunately, I have not been able to secure a copy of Portier’s 
book in time to review it in this article. However, I have perused 
Regaud’s and Guilliermond’s criticisms. From these criticisms it is 
apparent that Portier in 1918 stated a theory regarding mitochondria 
that coincides with a conception of these bodies that has been growing 
in my own mind. I was not ready to state this hypothesis until I 
had collected more evidence in its support. <A brief consideration of 
Regaud’s and Guilliermond’s criticisms is pertinent at this time. 
Obviously, the details of Portier’s evidence cannot be considered in 
this discussion. Regaud quotes the following resumé from Portier’s 
“Les Symbiotes”: ‘‘Chaque cellule vivante renferme dans son proto- 
plasme des formations que les histologists désignent sous le nom de 
mitochondries. Ces organites‘ne seraient pour mio autre chose que des 
bactéries symbiotiques, ce que je nomme des symbiots. . 
La bactérie symbiotique vient du milieu extérieur: elle peut, dans 
certains cas, y retourner et vivre d’une vie indépendante. Les bac- 
téries seraient done les seuls étres simples; tous les autres seraient 
doubles.” 
Regaud indicates various characteristics of mitochondria that are 
supposedly not shared by bacteria. He mentions the inconstancy of 
form of mitochondria, their behavior towards acids and metallic salts, 
their albumin-lipoid constitution, their fragility, the impossibility of 
mechanical extraction of mitochondria from the living cell, and the 
synthetic properties of mitochondria. He also indicates the following 
characteristics of bacteria that presumably, are not shared by mito- 
chondria: bacteria are definite organisms having a stable form (diffi- 
cult to change in shape); bacterial life is generally resistant to chemical 
and physical agents; bacteria are easily extracted mechanically from 
living cells without alteration of the form of the bacteria; the form and 
structure of bacteria and even their staining qualities are indifferent to 
fixation. 
I shall discuss briefly each of these characters that Regaud considers 
distinctive. 
1. Inconstanecy of form of mitochondria. This cannot seriously 
be considered a characteristic of mitochondria. It is a well established 
fact in bacteriological technique that certain bacteria assume different 
forms in different media (Jordan, ’20, p. 67). 
2. The behavior of mitochondria towards acids and metallic salts. 
In the second section of this paper I have given sufficient evidence that 
THE AMERICAN JOURNAL OF ANATOMY, VOL. 30, NO. 2 
