MICHIGAN ACADEMY OF SCIENCE. 
217 
Figure 9. 
Figure 10. 
Figure 11. 
Figure 12. 
Portion of a cross section of the same embryo 84Ba 
showing a germ cell (f) within the gut entoderm. 
Portion of a cross section of the same embryo thru the 
region of the hind gut showing three germ cells (f) 
in the gut entoderm two of which are undergoing 
mitotic division, and the other possessing a peculiar 
bilobed nucleus. 
Portion of a cross section of embryo 19Da showing sev- 
eral periblast nuclei (n) in the periblast layer (m). 
Portion of a cross section of the same embryo showing 
a yolk granule (o) in close proximity to a periblast 
nucleus (n). 
ON CERTAIN RELATIONS OF THE FLORA AND VERTEBRATE 
FAUNA OF GRATIOT COUNTY, MICHIGAN, WITH AN 
APPENDED LIST OF MAMMALS AND 
AMPHIBIANS. 
H. M. McCurdy. 
As there are so few reported records bearing upon the question of 
the distribution of the biota for the interior of the State of Michigan, 
the following notes and records are presented. These records are nec- 
essarily incomplete and additions will in time be made. It is believed, 
however, that they are of sufficient importance to direct attention to 
other areas in the interior and to modify to some extent the views gen- 
erally held concerning the relations existing between the interior and 
the border regions. 
In the literature on the geographic distribution of plants within the 
limits of the State, the differences are generally emphasized and have been 
in advance of the evidence. One is strongly and unduly impressed with 
the idea that the flora is decidedly more southern along the coasts especi- 
ally the west than in the interior at a given latitude. Ruthven 1 
while expressing this view, states that he does not find so great 
difference on the east side of the State as appears to hold for (he 
west side. For the regions of Sand point, Roscommon and Craw- 
ford counties and Manistee, Coons 2 states that the vegetation has ad- 
vanced in a V-shaped manner the central portion of the state lag- 
ging behind the border portion. “Of the eight species named by Coons, 
three, (Asimina triloba, Gleditsia tri acanthus, and Cercis canaden- 
sis) have not been reported north of that. The remaining species 
occur in the interior, in the latitude of Saginaw Bay. A more 
detailed study will doubtless reveal their presence still farther toward 
the north. The others mentioned are: Benzoin aestivale, Sassafras 
variifolium, Liriodendron tulipifera (rare), and Oelastrus scandens. 
It must be remembered that our knowledge has advanced northward 
muthven, Alexander G. et al. A Biological Survey of the Sand Dune Region on the South Shore 
of Saginaw Bay, Michigan, Mich. Geol. and Biol. Survey Pub. 4 Ser. 2 (1911). 
2 Coons, G. H. Sec. 1, p. 59. 
