JOURNAL OF MICROSCOPICAL SCIENCE. 



DESCRIPTION OF PLATE XXII, 



Illustrating Professor Ray Lankester's Memoir " On 

 the Structure of Haliphysema." 



Fig. Y.-^Haliphj/sevia Tumanowiczii, Bowerbank, drawn from a spe- 

 cimen, placed while living in weak chromic acid (^th per cent.), and subse- 

 quently preserved in strqng alcohol, pi. Streaming protoplasm investing 

 the spicula. esp. Spicules derived from Esperia. ren. Spicules derived from 

 Reniera. 



Fig. 2. — Protoplasmic core of a similar specimen, obtained by gently 

 crushing the test. The core as drawn is a restoration of a specimen 

 broken into three pieces. It is %QmQ'V}\isA> flattened, and therefore widened 

 by pressure. Anteriorly the egg-like bodies are seen embedded in the 

 solid protoplasm. The surface of the core is grooved or ribbed by the 

 longitudinally placed spicules forming the test. 



N.B. — Figs. 1 and 2 are magnified 135 times linear. 



Fig. 3. — A spicule of the test (derived from a Reniera) showing invest- 

 ment of streaming protoplasm. «. One of the vesicular nuclei. From a 

 specimen preserved in chromic acid followed by alcohol. 



Fig. 4. — Egg-like body ; from a similarly preserved specimen teazed. 



Fig. 5.— Vacuolated protoplasm and large and small corpuscles ; from a 

 similar specimen. 



Fig. 6. — Egg-like bodies from a similar specimen ; one is in the process 

 of transverse fission. 



Fig. 7. — Portion of the protoplasm showing the wall of cavities in which 

 egg-like bodies were embedded. 



Fig. 8. — Corpuscle similar to those of fig. 5. 



Fig. 9. — Vacuolated, reticular protoplasm, with a number of the cha- 

 racteristic vesicular nuclei embedded. From a chromic-acid-alcohol 

 specimen, teazed. 



Fig. 10. — Vesicular nuclei of Haliphysema, showing various forms of 

 collapse due to the action of reagents, a, b. Still spherical, c. Invagi- 

 nated hemisphere, d. False appearance of transverse septum and fission. 

 e. Lateral view of d. 



Fig, 11. — Portion of the core of a specimen hardened in \ per cent, 

 chromic acid, followed by alcohol, then stained with hsematoxylin, mounted 

 in oil of cloves and Canada balsam, and carefully crushed whilst in the last- 

 named medium. The vesicular nuclei, darkly stained, are seen besides 

 smaller corpuscles, c. Cavity from which a vesicular nucleus has been 

 removed, r. Ridges fitting into the interstices of the test. 



N.B .—Figs. 3 to 11 represent the objects of 280 times the natural size, 

 linear. 



