H. H. Howorth—The Fauna and Flora of the Loess. 207 
Dr. Nehring protests that he never confounded the Arctic Tundras 
with the sub-Arctic grassy herbed Steppes of South-western Siberia, 
adding, that he “knows very well that they (7.e. the former) display 
both a different fauna and different climatic conditions as compared 
with the southern grassy Steppes.” I never said Dr. Nehring had 
so confused them; but I certainly understood Baron Richthofen to 
treat them as the same for the purposes of his argument. 
Again, Baron Richthofen says in his answer to me: ‘There is but 
one great class of agencies which can be called in aid for explaining 
the covering of hundreds of thousands of square miles, in little in- 
terrupted continuity, and almost irrespective of altitude, with a 
perfectly homogeneous soil. It is those which are founded in the 
energy of the motions of the atmospheric ocean which bathes 
alike plains and hill-tops” (Got. Mac. Dee. II. Vol. IX. p. 297). 
Contrast this passage with the following by Dr. Nehring: “ That 
all deposits of Loess have been caused by sub-aerial means, I do not 
venture to maintain.” This is surely but scanty support. Dr. 
Nehring then. goes on to say, “ At any rate, the wind has played an 
important part in the formation of the Loess-like deposits of Weste- 
regeln, Thiede, and many other places in Central Europe.” It would 
have been gratéful to us if Dr. Nehring had enlarged this dogmatic 
statement by some evidence. How does he explain by the action 
of the wind the calcareous elements in Loess, its capillary struc- 
ture, its homogeneous character over wide areas, the absence from 
it of minute laminae such as occur in wind-drifted dunes, the presence 
in it of skeletons undecayed, etc., etc.?2 Whence does he derive the 
dust, and how does he make such accumulations of dust compatible 
with the growth of the,herby grasses that characterize the Steppes 
he defends? These are the questions I in common with others have 
asked, and I must not be remitted for an answer to oracular dicta 
reminding us of “the Syllabus.” Dr. Nehring says it is not out 
of the regions of possibility “to postulate for Central Germany the 
climatic conditions of Western Siberia and Hastern Europe.” Put- 
ting aside the fact, which I altogether dispute, that Dr. Richthofen’s 
arguments would apply to plains covered with long grasses like the 
Russian Steppes, instead of being deductions from the stony and 
bare plateau of what he well calls the Salt Steppes of Mongolia, I 
would join issue with Dr. Nehring even on his smaller postulate. 
The Loess occurs not only in Central Germany, but over a large 
part of France and in Spain. Is he prepared to argue that this 
peninsular area with its peninsular climate, having the West and 
South-west humid winds from the Atlantic continually passing over 
it, can, under any possible conditions, have had a climate like that 
of an inland continental district, like that of the Asiatic Steppes? If 
so, let us by all means have the evidence. 
Perhaps he bases his view on the previous paragraph in which he 
contends that at that time Germany was more distant from the 
Atlantic than now, and that Europe extended itself further west 
and south-west. This again (if Dr. Nehring means a substantial 
extension westward) I must dispute, unless he have some evidence 
