THE AMERICAN LOBSTER. 
149 
VARIATIONS IN OTHER ORGANS. 
ROSTRUM. 
I have met with a single case of bifurcated rostrum, a small male, represented 
in figs. 102, 103. The median groove, which corresponds to an area of absorption in 
the shell (see p. 88), divides near the apex, each branch going to a terminal spine. 
Instead of a single spine below the terminal, there are several smaller ones. 
In Alpheus saulcyi the median rostral spine is sometimes wanting, as in the genus 
Betieus, of Dana. (See 94, p. 384, plate xxii, fig. 11.) 
OVARY. 
Two instances were observed in which the ovarian lobe on one side has suffered 
division, one that of a small female (44 mm. long, fig. 131, plate 38) in which one 
of the posterior lobes is involved, the other an adult lobster (fig. 164, plate 42) with 
similar division of the left anterior lobe. 
HERMAPHRODITISM. 
A malformed hermaphrodite lobster, Homarus gammarus, was described and fig- 
ured by Nicliolls in the Philosophical Transactions of the Royal Society of London 
in 1730 (141). “The specimen,” he says, “if split from head to tail, is female on the 
right side and male on the left side.” This was true of both the internal and external 
organs. A similar case of hermaphroditism has been described by Gissler (78) in the 
Phyllopod Uubranehipus vernalis. 
La Valette St. George (193) discusses a very interesting case of t hermaphroditism 
which he discovered in the crayfish. He found eggs present in the nearly ripe testis 
of Astacus fluviatilis in July and August. The eggs were placed usually at the 
periphery of the testis lobe. They were round or oval, 0.06 mm. to 0.015 mm. in diam- 
eter, and showed the usual constituents of ovarian eggs. They had a larger germinal 
vesicle than the normal egg, were sometimes inclosed in a follicle, and contained yolk 
spheres. He asks how the presence of the eggs in the normal testicle is to be explained 
and gives the following answer: 
These eggs are evidently derived from spermatogonia, which have become unfaithful to their 
original functions. Instead of multiplying by division to form a number of spermatocytes, they have 
chosen a shorter way, which makes it possible for a single egg to arise from them by simple growth. 
Under certain conditions a primitive sperm cell may be converted into an egg 
cell, and this, he says, furnishes a new proof of the relation of spermatogonia and 
oogouia. Follicle cells may arise from a spermatogonium, but the latter can never 
arise from follicle cells. 
The spermatogonia, according to La Yalette St. George, produce, chiefly by mitosis, 
the spermatocytes, which eventually give rise to the spermatids. Spermatosomes, as 
well as large follicular nuclei, may be found in the process of degeneration in the testis. 
Hermaphroditism has also been described in the lobster by Hermann (89), who, 
according to La Yalette St. George, was the first to prove the presence of hermaphro- 
ditism in the testes of decapods. Hermann discovered in the anterior parts of the 
testis of the lobster large round or oval cells with granular protoplasm, each pos- 
sessing a large germinal vesicle with nucleoli. Eight or ten such cells, which were 
regarded as undoubted eggs, were found in one specimen. In some of the figures 
given by La Yalette St. George the ovum fills nearly the entire lumen of the testis. 
