COURTSHIP OF THE GREAT CRESTED GREBE. 529 
(chiefly Arundo phragmites) along one shore, affording cover for 
the nests of the Grebes, while the banks of the other two are 
bare. One of these latter is, however, very rich in fish, and a 
number of Grebes come over every day to feed on it. There, 
of course, they are nowhere near their nests, and this is of some 
importance in connection with the meaning of their courtship- 
actions. 
As there were thirty pairs or more on the water, I was never 
at a loss for “material.” In fact, it was often very hard for my 
pencil to keep up with the birds’ actions. 
Some of the watching was done concealed in the boathouses, 
and some from a screened punt, but the major part from the 
bank. This is in many ways the most useful. With ‘good 
instruments * (in this case Goerz-Trieder binoculars x12 and a 
telescope x30) every action can be easily followed, the birds 
are not seared, the field of view is uninterrupted, and it is far 
easier to follow the actions of the same pair of birds for a long 
period of time. 
This, as I say, is best for discovering the general course of 
events; but just as the microscopist must for certain details 
supplement his low-power lens with an immersion objective, 
so here, watching at close quarters must be adopted in order 
to work out the exact meaning of each separate bit of behaviour. 
Only when the general course of events has been roughly traced 
and some hypothesis, however vague, framed concerning it in 
the watcher’s mind, can the fine shades of behaviour have any 
meaning for him. It is impossible to notice or record everything, 
and only when some general idea has been gained can the value 
of any fact be properly appreciated. It is on this account that 
IT would say, always begin by distant watching; otherwise you 
will not be able to see the wood for the trees. 
My brother, Mr. N. T. Huxley, spent much time watching, 
and several of the incidents here recorded are from his notes. 
His help was most valuable, and I wish to acknowledge it here. 
To Mr. James Street, Head Keeper at the Tring Reservoirs, I 
am indebted for much information, and for his help in arranging 
hiding-places, ete. 
8. ABSTRACT OF SELOUS’S WoRK. 
T venture to append a short abstract which I had to make of 
Selous’s diary notes for my own use, in hopes that others may find 
it useful too. 
* A simple apparatus, which makes the task of simultaneous note-taking and 
observation very much easier, may be constructed as follows :—On to a folding 
camera tripod is screwed a ball-and-socket camera-holder (special telescope-holders 
can, I believe, be purchased) ; the field-glasses are clamped, by means of a long 
screw and nut, between two leather-lined pieces of wood, and the lower piece of 
wood can be screwed on to the platform of the ball-and-socket. Both for stationary 
and moving objects the fatigue of observation is enormously lessened hy this means ; 
in addition, one or both hands are left free, and so notes can be taken while 
watching—a necessity, almost, for reliable work. 
