EFFECTS ON THE HIGHER INVERTEBRATES 47 



tion upon the mitochondria in Ascaris megalocephala. The normal muscle cells 

 of the body contain mitochondria, chiefly of filamentous form, but granular in 

 the perinuclear region. "When starvation begins, however, the filamentous 

 forms become granular ones, some by diminution, others seemingly by segmen- 

 tation, while still others by the fusion of two or more of them may form globules, 

 clumps, etc., usually connected by supporting fibrils; in short the whole number 

 and quantity of mitochondria gradually diminish to a very small minimum at 

 the end of about 10 days starvation." Similar results were observed also in 

 the epithelial cells of the intestine. 



ANNULATA 



Relatively little attention has been paid to the effects of inanition upon 

 the annelid worms. Apparently only the Hirudinea (leeches) have been studied 

 in this respect, aside from a single reference to the Chaetopoda. 



Chaetopoda. — In connection with the previously mentioned study of the 

 effects of calcium-inanition on sponges, Maas ('12) noted that in calcium-free 

 water a reduction of the calcareous substance without injury to the soft parts 

 may likewise occur in the tubeworm, Spirorbis. 



Hirudinea. — Only a few data, chiefly physiological, are available concerning 

 the effects of inanition upon the leeches. Valisnieri is cited as authority for 

 the statement that Hiriido medicinalis requires three years for death from starva- 

 tion. Some observations by Cajal ('04a) and Dustin ('06) on the nerve cells of 

 fasting leeches will be stated in Chapter X. Bialaszewicz ('19) found but slight 

 decrease in the fat of leeches during starvation. 



Putter ('11) states that in the blood-leech one meal of blood may last six or 

 seven months, and that an additional six or seven months or more of fasting may 

 be endured without the slightest injury. Weber ('14) says the blood-leech has 

 an enormous gastric capacity (five or six times the volume of the entire empty 

 body) and may not feed for months. 



Smallwood and Rogers ('10) noted that the leech Semiscolex kept without 

 feeding for long periods gradually decreased in size. When the nerve cells from 

 such starved animals are examined, either fresh or in stained sections, great 

 changes are noted. "The whole cytoplasm of the cells has the appearance 

 of a coarse foam structure. Here and there may be found the remnants of 

 previously existing solid particles of stored up material." These particles were 

 interpreted as food material, which is consumed during starvation. 



Similarly in the fish parasite, Pisciola, Erhard ('n) observed that droplets of 

 glycogen occur normally in the glia tissue around the large ganglion cells. After 

 three days of starvation, however, the droplets of glycogen begin to decrease 

 around the nerve cells, but now appear in the cells. Glycogen is said to behave 

 similarly also in other parts of the body. 



ECHINODERMATA 



The investigations of inanition in the Echinodermata have concerned 

 chiefly the effects of partial inanition (various salt deficiencies) upon the develop- 



