As far as I can see, it would be extremely difficult to change through selection the one form of inheritance into the other.
But from the circumstance of colour being so variable, and from its having been so often modified for the sake of protection, it is extremely difficult to decide in how large a proportion of cases sexual selection has come into play.
Diagnosis of fracture of either of the bones of the foot is, as we have said before, extremely difficult.
Again, careful though we may be with the probe, it is extremely difficult to be certain that we have discovered the whole extent of any fistula.
When the os corona alone is fractured then diagnosis is extremely difficult, the smallness of the bone and the comparative rigidity of the parts rendering manipulation almost useless, and effectually preventing the obtaining of crepitus.
The capture of this bird is extremely difficult, as it is exceedingly shy, and ever on the alert against approaching danger, which it eludes by seeking shelter amongst the fastnesses of its favourite rocks.
This species builds in holes in rocks, walls, or roofs, and with so much precaution are their retreats selected that it is extremely difficult to find a nest.
Even in the north it is extremely difficult to find them, and for the first description of one we have to thank Boja, whose statements have been corroborated by Schräder.
It is extremely difficult to ascertain the origin of these reports, which are so involved in metaphor that the signification is not intelligible to Europeans; their existence is not doubted, however, in Africa.
In the absence of any history of the case it isextremely difficult to fix the origin of a suppurating tumor originating, apparently, in the depth of the right hypochondrium.
It is extremely difficultto separate an abscess in the abdominal wall, in the right hypochondrium, or a tumor in this region, from an abscess of the liver.
Many cases of gastric cancer associated with ascites have been falsely diagnosed as cirrhosis of the liver, and sometimes the distinction is extremely difficult or impossible.
In almost all experiments on the crossing of animals there are so many causes of doubt, that it is extremely difficult to come to any positive conclusion.
Indeed, he walked at such a pace, old man though he was, that at times I found it extremely difficult to keep up with him.
I tried to promenade the deck, only to find that the vessel's rolling rendered it extremely difficult, if not well-nigh impossible.
I despatched you post haste to a chemist with a prescription which I thought would be extremely difficult, if not impossible, for you to get made up.
It is very often bent or folded, and even more often faulted; the faulting may be of great complexity, making it extremely difficult to follow the vein.
It is comparatively easy to measure known reserves; but a quantitative appraisal of the probable and possible reserves for the future is extremely difficult.
The existence of criminality in the family is of still greater importance, but it is extremely difficult to obtain any information on this head, either from the patient himself or his relatives.
Mr. George soon realised that however easy it is to exercise a beneficial influence on one or two boys by adopting gentle methods, it is extremely difficult to manage hundreds in this way.
The obligation to make adequate compensation for the injury caused would be an ideal punishment, but is extremely difficult to put into practice.
Rath, of Zetterfeld, has lately described a case of extremely difficult labour, in consequence of twins united by the breast.
On the other hand, we sometimes meet with the os uteri in a second pregnancy so little altered by the effects of the previous labour, that it would beextremely difficult to come to a decision.
I know it is extremely difficult to define the line between social habits and enjoyments perfectly innocent and proper and those that are injurious to all concerned.
The operation may be extremely difficult, as the antrum is frequently of small size and very deeply placed.
In other cases, owing to the thickness of the bony walls or to the narrowness of the canal, it is extremely difficult.
Certainly it is extremely difficult to find any form of the idea of God which has retained a purely spiritual or religious character throughout the entire course of its history.
But other pupae, although not, perhaps, quite so arduously placed as in the last instance, nevertheless present us with anextremely difficult puzzle, as to how the included insect is to be extricated from its swathing bands.
It is very difficult to catch the insects in which the expansion of the wings is best observed at the right moment; and even then it is extremely difficult to say whether one cause more than another may contribute to this phenomenon.
They began to thin it by tearing away some threads of silk where they wished to pierce it, and at length by dint of pinching and biting this tissue, so extremely difficult to break, they formed in it a vast number of apertures.
But as a matter of fact, it is extremely difficultto place a shrapnel shell so as to consummate this end.
A moving object, particularly when its oscillations are irregular and incalculable, is an extremely difficult object at which to take effective aim.
Dropping bombs from aloft appears to be a very simple operation, but as a matter of fact it is an extremely difficult matter to strike the target, especially from a high altitude.
An aeroplane travelling at a high speed, and pursuing an undulating or irregular trajectory is almost impossible to hit from the ground, as sighting is so extremely difficult.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "extremely difficult" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.
