PROCEEDINGS OP THE PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
77 
it occurred frequently that the two organisms resulting 
from this simple fission exhibited the characteristic eugle- 
noid movements some considerable period before they were 
released from their cyst, and furthermore exhibited the 
well-known eye spot at this early stage. The rupture of 
the enclosing walls released two perfect Euglenas. 
The other method is one less frequently observed, 
but of very great interest, as being of a like nature 
to what has been described in certain very minute 
Infusoria of the flagellate group. After a prolonged 
period of encystment, the contents appear to be segre¬ 
gated into a great number of minute, irregular-shaped 
bodies, which, on the rupture of the cell wall, escape 
and creep about actively with amoeboid movements, each 
of these becoming in time an adult Euglena. 
There is still another mode of reproduction, by repeated 
division, which takes place during the winter months, 
and principally provides for the coming season’s stock. 
At this stage of my researches I was so fortunate as 
to discover a pond which supplied me with three or four 
other species of the genus Euglena, most of them of larger 
size than viridis, and consequently more easy to study. 
These species were E. spirifer, E. deses, and E. rostrata. 
[Prof. Harker described the special features of these species 
by the aid of coloured diagrams.] 
In the largest of these I succeeded in finding a con¬ 
tractile vesicle exhibiting systolic and diastolic action—an 
organ characteristic of Infusoria. 
On applying various chemical tests to these Euglena:, 
I have been utterly unable to find the presence of 
any starch : the reactions are precisely similar to those 
given by all animal organisms, iodine turning them brown, 
and this notwithstanding the fact that the green colour¬ 
ing matter of the Euglenidce is chlorophyll. With Algoe, 
the reaction given by iodine invariably shows the presence 
of starch. I have applied this test in many hundreds of 
cases : first of all, with every species of green-coloured 
Algae that I could procure ; in the second place, with not 
only the Euglenidce, but all such green-coloured infusoria 
as Phacus and Trachelomonas, with a like result. 
Aboutthis time, almostsimultaneously, Stein, in Austria, 
and Kent, in England, succeeded with an experiment which 
may be said to set at rest the question of the position of 
Euglena. They supplied it with particles of carmine, just 
as in the laboratory we are in the habit of feeding some of 
the larger infusoria, and succeeded, under very high powers 
of the microscope, in actually watching individual specimens 
ingest solid particles of carmine. This was performed 
through a very minute orifice, situated at the bottom of 
the notch already described, from the vicinity of which 
springs the flagellum, and which, therefore, is a true 
mouth. In the larger species, E. deses and E. spirifer, I 
have succeeded in watching a similar act, and noticed that 
the flagellum played a prominent part in aiding the 
operation. 
I have by various chemical processes, which I need 
not at present detail, separated from Euglena both 
chlorophyll and xanthophyll. This very interesting 
question of the colouring matter undoubtedly suggests a 
vegetable affinity, but we must bear in mind that other 
animals are coloured green by chlorophyll, too. 
To sum up; both by its mode of progression and repro¬ 
duction, the flexibility of its cuticular layer, the chemical 
reactions of its substance, its modes of taking food, we 
are led to the conclusion that Euglena is properly classed 
by Stein as a Flagellate Infusorium. 
4* 
SUMMER SESSION, 188 2. 
The following Excursions were made:— 
June 3rd. 
1, Logierait. 
The ground selected for exploration was the banks 
of the River Tay between Logierait and Dunkeld, 
and the party was under the leadership of Dr Buchanan 
White. As may easily be imagined by anyone familiar 
with any part of the banks of our noble river, these 
present to the naturalist a rich field for observation in 
almost every department of natural history. Strange 
to say, however, these banks have not been explored 
so exhaustively as would have been expected, and conse¬ 
quently it has been left to the Society to carry out a 
thorough exploration of this comparatively untrodden field. 
But from the great extent of the ground, and as a rapid 
traverse of it is not sufficient for the purpose, it will still 
be some time before even a superficial examination is made. 
Looking at the river banks from a botanical point of view, 
a walk from, say, Invergowrie to Dunkeld, would give a 
