76 
PROCEEDINGS OP THE PERTHSHIRE SOCIETY OP NATURAL SCIENCE. 
Mrs Baxter, St Leonard’s Bank ; Mr Joseph Munro, 
Queen Street, Craigie ; Mr Robert Dow, Stewart’s Free 
School; Dr Trotter; Dr Urquhart; Mr J. P. Whittet; 
and Mr T. Love. 
DONATIONS. 
The following donations were intimated:—Skull of a 
mole—by Mr James Stewart; fern rhizomes—by Mr 
Sutherland, Peel ; a jay—by Mr Young, Preeland ; a 
woodcock—by Mr Graham, Kildinny; a merlin hawk— 
by Mr Logan, Rannoch ; a wheatear—by “M.R.S.,” 
Rannoch; tawny owl, chaffinch, creeper, thrush’s nest and 
eggs, a wren, and a hedge-sparrow—by Mr M'Lean, 
Murie House; and two hedgehogs—by Colonel Drum¬ 
mond Hay. 
THE LATE MR DARWIN. 
Dr Buchanan White said the Society should not allow 
this opportunity to pass without putting on record its 
deep regret at the death of the foremost naturalist of the 
age, Mr Darwin. It was not necessary that he should 
enter into any eulogium of Mr Darwin, as he was well 
known all over the world; and, therefore, he simply 
moved that the Society record in its minutes its unfeigned 
regret at his death, and its admiration of bis work. 
Mr John Young seconded, and the motion was unani¬ 
mously agreed to. 
The following paper was read :— 
“On the Animal Nature of Euglena viridisfl By 
Professor Allen Harker. 
If we collect from stagnant ponds, or even from our 
rain-tubs at this season of the year, specimens of the 
water, we shall, in all probability, find it tinged of a 
bluish green colour; and on an examination of this 
coloured water, we shall generally find that this green¬ 
ness is due to the presence of a moving green-coloured 
organism, about the 500th of an inch in length, which 
is known as Euglena viridis. It is cylindrical in form, 
tapering to a point at the posterior extremity, and 
abruptly rounded at the anterior pole; near the latter is a 
minute notch, from which springs a long flexible hair-like 
organ, termed the flagellum, which is constantly kept in 
motion, and by its lashing propels the creature through 
the water with a rolling action around the longer axis of 
its body. The body seems to be partially made up of 
granular structures, and near the anterior extremity is a 
brilliant crimson or red spot, characteristic of many of 
the lower forms of both animal and plant life. Hp to 
within a few years ago considerable doubt existed as to 
whether this organism was an animal or a plant. Yon 
Stein had, indeed, always described it as a flagellate 
infusorium, but others had again considered it a plant. 
Huxley, in his Anatomy of the Invertebrates, while allud¬ 
ing to it as an infusorium, had said, “Euglena may 
turn out to be a plant,” and until recently, it was given as 
an example of the motile condition of an alga in some of 
our public schools of botany. Pour or five years ago, I 
took up the study of these organisms, and, after some 
time, became so convinced of their animal nature, that I 
carried out a long series of observations and experiments 
on them, which cannot yet be said to be completed. 
Some of those results are now oflered to your notice, to¬ 
gether with contemporaneous observations of Kent and 
Stein, which have settled indubitably the animal character 
of the Euglenidce. 
In the first place, the behaviour of the creature in its 
active condition, while exhibiting some features sugges¬ 
tive of the motile condition of an alga, at the same 
time exhibits striking differences. Notably in its be* 
haviour while swimming through the water, and in 
coming in contact with obstacles to its progress, Euglena 
has the power of contracting the outer layer of its body, 
and creeping round or under and over an object in its path, 
while any motile plant, such as a diatom or a zoogonidia, 
progresses only in a straight line, and, meeting with an 
obstacle, invariably backs away, and takes up the same or 
another direction in a straight line. This flexibility of the 
body is quite an animal character. This property of 
Euglena gives rise, too, to its habit of assuming a variety 
of forms, from its usual elongate, spindle shape, to some¬ 
times that of a perfect spherical one. It very frequently 
becomes repent, and crawls over the surface of the field; 
some species, indeed, never assuming any other mode of 
progression than this repent form. Any one watching this 
rapid change of form in Euglena, varying at almost every 
moment, cannot fail to be reminded of the behaviour of 
undoubted infusoria, such as the ciliate Paramecium or its 
flagellate congeners. The long flagellum, again, is unlike 
any structure possessed by an alga in any stage, the cilia 
of motile spores in Protococcus, &c., being temporary in 
character. 
In keeping Euglena in bottles, a time soon came when 
a permanent change took place, the creature assuming 
a spherical form (the flagellum disappearing) and falling 
to the bottom. It might at this stage surround itself 
with a coat of a yellow substance, whose composition 
is not known, and in this encysted condition reproduce by 
two distinct methods. The first is by simple fission, and 
this seems to be very common. During these observations 
