ANATOMY, HISTOLOGY, MORPHOLOGY, AND PHYLOGENY. Ech. 13 
pended amoeboid corpuscles, of one kind only, which contain a substance 
allied to haemoglobin, termed “ haemoxanthin ” by the author. The 
corpuscles originate from lymphatic glands ; these are the ovoid gland 
for the vascular system and body cavity, and Tiedemann’s bodies 
and the Polian vesicles for the water- vascular system. All these 
lymphatic glands consist of a connective tissue stroma supporting cells, 
which multiply rapidly and wander away as amoeboid corpuscles. Ambu- 
lacral apparatus (pp. 73, et seq.). Tiedemann’s bodies (p. 75). Polian 
vesicles (p. 76). Stone canal (p. 77): most of the pores of the madre- 
porite open into the stone canal, the remainder into the peripheral cavity 
belonging to the blood-vascular system. Modifications of the water- 
vascular system in different groups (p. 78). Blood-vascular system (p. 86) 
(= perihoemal system of Ludwig, vide infra) : the oral ring opens into 
the body cavity in each interradius. In each arm there are a radial, two 
marginal, and as many transverse vessels as there are feet on each side. 
The radial and marginal vessels send vessels to the feet. The marginal 
vessel also sends off a vessel opposite each tube foot, which opens into the 
body cavity of the arm, between the ambulacral and adambulacral pieces. 
The oral ring sinus and the radial sinuses are alike divided in half by a 
septum. In one interradius a large sinus rises from the ring sinus towards 
the aboral face, the “ axial ” or “ glandular sinus,” containing the stone 
canal and ovoid gland. The ovoid gland consists of lymphatic tissue, and 
has a prolongation which hangs free in the body cavity, but has no 
connection with the stomach, as Hamann supposed. The axial sinus 
communicates with the exterior by some of the madroporic tubules. 
Genital vascular apparatus (p. 94) : in the young Astropecten there is, at 
first, no aboral blood ring. Then the axial sinus sends out on each side a 
prolongation containing a process from the ovoid gland — the genital 
rachis. These processes grow round the aboral face of the animal, 
forming the aboral blood ring, containing the annular genital rachis. 
From the ring arise in each interradius two outgrowths, into which the 
genital rachis is prolonged, and from the prolongations of the geuital 
rachis sprout the ten gonads. The genital ducts arise as ingrowths of the 
ectoderm. The portion of the genital rachis not used to form gonads 
forms lymphatic tissue, like that of the ovoid gland, supplying the 
genital vascular apparatus with corpuscles. 
All that the author describes as blood sinuses are, in Ludwig’s termino- 
logy, “ peribmmal spaces,” and be finds that Ludwig’s “ blood-vascular 
system ” has no existence as such. Ludwig’s “ radial blood-vessel ” is a 
series of lymphatic spaces in the septum of the radial blood-vessel proper ; 
his oral blood ring in the annular buccal septum does not exist ; his aboral 
blood ring and genital vessels are lymphatic organs produced from the 
genital rachis. 
Modifications of the blood- vascular system in different groups (pp. 100, 
et seq.). The blood-vascular system of Echinoderms is derived from the 
general body cavity, but is homologous with that of other Echinoderms. 
Sexual Reproduction (p. 113). Gonads of different families described 
