404 
E. KAY LANKESTEK. 
picro-sulphuric solution, followed by alcohol, and was not treated with any 
staining reagent ; consequently tbe brown pigment of tbe atrial tunic, which 
was richly developed in this specimen, was very obvious, as shown in the 
figure. Artifact spaces, together with the natural lymph-spaces in the 
neighbourhood of the notochord and nerve-cord, have produced a distortion of 
this region. The space marked “ artifact space,” on the left of the figure, 
is incorrectly labelled, being probably a natural lymph-space (myoskeletal 
lymph-space) slightly distended by the action of reagents. 
Fig. 4. — Untouched sketch of a section through the branchial region of a 
female Amphioxus at the breeding season. The specimen was treated with 
Muller’s fluid, followed by alcohol, and is remarkable for the great distension 
of the epipleura by the enlarged gonads, leading to obliteration of the meta- 
pleural ridges and canals and of the ventral plaits. The pharynx was badly 
preserved, and the sub-notochordal region much distorted. The artist has 
represented these parts in a rough and undetailed way. 
Fig. 5. — Diagram of a portion of the body of Amphioxus, from which the 
notochord, roof of the pharyngo-dorsal coelom, and upper part of the myo- 
tonies have been removed by horizontal section, so as to show the atrio- 
coelomic funnels in position. A rod is passed from the peri-enteric coelom into 
the pharyngo-dorsal coelom. 
Fig. 6. — Enlarged transverse section of an atrio-ccelomic canal, to show the 
cell structure, after staining with hsematoxylin. 
Fig. 6'. A piece of the same before staining. 
PLATE XXXYI. 
Diagram of a transverse vertical section through an adult female Amphioxus 
at the region of the atrio-ccelomic funnels. The muscular tissue is coloured 
yellow, the connective tissue and gonad cells purple, the hypoblastic cell-layer 
and notochord green, and the atrial epithelium light brown ; the epidermis 
and nerve-cord are uncoloured, as also are the clots present in the meta- 
pleural canals, the fin-ray space, the pharyngo-dorsal ccelom, the myoskeletal 
lymph-spaces, and the dorsal aortse. 
The drawing is intended especially to show the form and position of parts 
when corrected from drawings of actual sections, so as to allow for local 
shrinking and distortion. The correct estimation of the spaces found in 
sections between the skeletal sheath of the notochord and the muscular tissue, 
and again between the latter and the neural skeletal tube and its skeletal crest, 
is exceedingly difficult, ar.d has perhaps not been altogether rightly carried 
out. It has been necessary to select a particular section for illustration, the 
myo-skeletal lymph-spaces and the position of the inter-muscular septa being 
necessarily different in each one of a series of sections traversing a given 
segment of the organism. The seel ion selected shows part of a posterior 
