BILL AND HAIRS OF ORNITHORHYNCHUS PARADOXUS. 145 
trace the endings of the nerves. The authors have, however, 
relied almost entirely upon photomicrography for their illus- 
trations, with the result that the figures upon two (xxiv and 
xxv) out of the three plates are utterly worthless, and convey 
a most inadequate conception of the appearances presented by 
the sections. It is evident from the descriptions that the 
sections relied upon were adequate, and perhaps the negatives 
and the first impressions were also satisfactory: but in the 
form in which the paper reaches the public there is something 
inconsistent in the confident references made in the text to the 
representation of detail in a figure which turns out on inspection 
to be the merest smudge (see especially fig. 5, pl. xxiv, which, 
among all figures ever published in scientific papers, must surely 
take the palm for obscurity). My sympathies are entirely with 
those who have been misled into trusting a process which for 
this purpose appears to be entirely useless. The authors have, 
however, made some drawings, the photographic representa- 
tions of which are infinitely better than those of the sections. 
Fortunately, too, these figures, which are all to be found on 
the last plate (xxvi), deal with points of structure which needed 
the fresh tissues for their adequate treatment, and are there- 
fore unrepresented among my illustrations. 
I therefore propose to publish my figures together with their 
explanation (in the “Description of Plates”) exactly as I wrote 
them in 1892, except for mere verbal corrections, &c. Thus 
my description of the push-rods is entirely independent of that 
recently published in Australia, although it will be found that 
the two accounts are in substantial agreement. 
The gland-ducts and their associated hair-like and nervous 
structures are not alluded to by the above-mentioned authors. 
This is to be regretted, inasmuch as many of the most important 
points can only be decided by the use of the fresh tissues. A 
detailed description of these, so far as it is possible with the 
material at my disposal, is also given below, and the same is 
true of the hairs covering the body of the young and mature 
animal, 
The material upon which all the work described below has 
