IflS] Jolnisnit: Tlic i'ulHrntidii of Tissues from Aiujihibiaiis CA 



was not as great or a.s long ('ontiiuied, as in cells attached to the 

 tissue itself. 



On several occasions vigorous tissue showing gill-like outgrowths 

 were tested as to their response to heated pins placed just above and 

 near them on the top of the cover-glass. Always vigorous contractions 

 resulted if the pins were placed directly over them ; if the pins were 

 placed to one side the outgrowths would bend away from the stimulus 

 until they came up against the main body of the tissue; if the hot 

 pins were then placed on the opposite side tliis same gill-like struct\u-e 

 would retreat in the other direction. This response contiiuied for 

 several times, when ajiparently from exhaustion, or too great heat, 

 it gradually ceased. 



Dozens of cultures were kept active from fifteen to twenty days; 

 several from twenty to thirty days; three for thirty-three days, and 

 two thirty-six days and forty-one days respectively. Both these latter 

 ones were connective tissues and accidently dried up from faihire to 

 seal them up tightly by vaseline. The indications are that they would 

 otherwise have continued activity for a much longer period. 



SlIiLMARY 



1. Nerve-growth observations indicate an out-pulling of nerve fiber 

 rather than an out-pushing. Progress outward is by means of pseudo- 

 pod-like processes. 



2. Gill-like structures appear on tissues from the head region of 

 the body. 



3. Plat drops of serum produced better results than deep rounded 

 drops, causing tissue to be up against the solid cover-slip; they afford 

 also better conditions for study with an oil-inunersion lens. 



4. A common Stender dish with moist cotton in the bottom offers a 

 good way for cultivating a large quantity of tissue. 



5. At other points than at the tips of outgrowths, bactei-ial infec- 

 tion at first increases activity. 



6. Diemyctylus tissues thrive best when washed in Ringer's solu- 

 tion and transferred about every two days to a fresh medium. 



7. Increased toxic condition of serum and tissue causes decreased 

 heart activity. The heart beat increases in proportion to the increase 

 of temperature. 



