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W. C. TWISS 
into two equal parts and the development of these two sacs of mitochondria 
into two long threads of mitochondria in the spermatozoon." 
There has been a tendency, especially among the earlier observers of 
mitochondria in plant cells, to ascribe to these bodies a nuclear origin. 
A perusal of the literature clearly indicates that the work of Goldschmidt 
( '04) is largely responsible for this, though the inception of the chromidial 
hypothesis doubtless owes its origin, as Dobell ('09) states, to the work of 
R. Hertwig, supplemented by that of Schaudinn, dealing with the occurrence 
of such bodies in the protozoa. 
Meves ('04), working with the tapetal cells in the anthers of Nymphaea 
alba, is credited with having made the first observations of mitochondria 
in plant cells. Meves shows two very clear-cut and beautifully drawn 
figures, of which his description is as follows: ''Enthdlt sie lange, unregel- 
mdssig gewundene, ziemlich dicke Fdden, welche sich mit Eisenhdmatoxylin 
intensiv schwarz gefdrbt haben. Diese Fdden konnen nicht wohl etwas anderes 
sein, als die von tierischen Zellen bekannten Chondromiten.'' 
It is not so much the question of origin, whether sui generis or chromidial, 
however, that has engaged the attention of later workers upon plant mito- 
chondria, as that of their relation to other structures in the cell and of their 
universality. Lewitsky and Pensa, working independently, have advanced 
a contention which promises to furnish material for controversy for some 
time to come. 
Lewitsky ('10) studies the root-tip and stem- tip of Asparagus officinalis 
treated according to the Benda method and stained with both the Benda 
stain and haematoxylin. He finds mitochondria corresponding to those 
described in animal cells, both in general appearance and in staining reac- 
tion, with no evidence whatever of a nuclear origin. The mitochondria 
appear short and rod-shaped, in the dermatogen; somewhat larger and with 
a tendency to swell at the ends, in the second layer; still larger in the third 
layer, while deeper in the assimilative tissue "dumb-bell" forms are seen, 
"similar to those well known in division figures of the chloroplasts." 
Next, still larger bodies are shown w^hich appear as if they have rome from 
the separation of the two halves of the ''dumb-bells." These are followed 
by figures of the young chloroplasts, and finally by the mature bodies. 
Meanwhile, the earlier forms of the mitochondria, combined with the 
"division figures" of the intermediate regions, lead him to conclude that 
the mitochondria are the Anlagen of the chloroplasts. Upon fixing some of 
the same material in alcohol and acetic acid, Lewitsky found that the mito- 
chondria were no longer to be seen in the cells, while the chloroplasts ap- 
peared as usual. This is taken as evidence of a chemical as well as a mor- 
phological transformation of the mitochondria, in producing the chloro- 
plasts. 
Guilliermond ('11, '13, '14) has published a number of papers in which 
he describes the mitochondria in all sorts of plants, his purpose being, on 
