A. Porter 
243 
had not been established, by including bis parasite in any of the already 
existing genera, “the danger is present of giving a total misconception 
to the life cycle of other forms.” Again, Miller’s work on Hepatozoon 
has not yet been confirmed, and there is the possibility that the phases 
described as those of Hepatozoon in the mite, Lelaps echidninus , may be 
phases in the life history of a parasite natural to the mite itself. This 
matter I have already discussed sufficiently in Science Progress. Until 
Miller’s work on Hepatozoon be confirmed, it seems to me well to reserve 
definite judgment on the sporogony of mammalian Leucocytogregarina. 
The relevancy of certain remarks in the footnote on p. 66 regarding 
Piroplasma and Trypanosomes, as well as their accuracy, may also be 
questioned. Two main chromatic bodies occur in a Trypanosome. The 
larger of these is commonly called the nucleus or trophonucleus, the 
smaller is generally designated the blepharoplast or kinetonucleus. The 
latter body is near the origin of the flagellum and is generally considered 
to be concerned with regulating the function of movement. Mr Wenyon 
calls this small body the “ micronucleus V’ a term usually associated 
with the small mass of generative chromatin of a Ciliate such as 
Paramoecium, which body has no connection with locomotion. 
Again, the law of priority is not a strict law (proved hypothesis), but 
a convention or rule, which, in addition to serving its primary purpose, 
has brought about much confusion and controversy, and must, of neces¬ 
sity, with increase of knowledge, be displaced. For instance, the familiar 
Coccidium is no longer designated as such owing to the strict application 
of the law of priority, while the equally well known Piroplasma should 
give place to Babesia. The vexatious use of the rule of priority has 
already been protested against by many of the greatest living zoologists, 
Lankester, Shipley, Minchin and Boulenger among others, and will 
probably be soon superseded by less rigid yet equally correct con¬ 
ventions. In the meanwhile, it is neither presumption nor crime to 
suggest a more reasonable nomenclature, for the world has long since 
dispensed with such inelastic codes as “ the law of the Medes and 
Persians which altereth not.” 
1 The reproductive character of a mieronucleus has been emphasised in the classification 
of the Protozoa as set forth by Doflein and by Hickson. The Protozoa are ranged in two 
great groups:— 
I. The Plasmadromata (Doflein, 1901), Protozoa in which the nucleus is not separ¬ 
ated into reproductive (micronucleus) and non-reproductive (macronucleus) portions. 
II. The Heterokaryota (Hickson, 1903), Cilioplwra of Doflein, Protozoa possessing 
cilia either throughout life or only in the early stage of the life cycle, but always with 
a micronucleus which is entirely reproductive in function; and a macronucleus which is 
trophic and kinetic. 
