Letter | Published:

A Natural Population of Anomalous Branched Tapeworms, Hymenolepis nana (Cestoda : Hymenolepididae), in a Colony of DBA/1 Mice

Naturevolume 191pages297298 (1961) | Download Citation



DURING work on metabolism of the dwarf tapeworm of mice (Hymenolepis nana), a natural infection with this parasite was found in a local colony of DBA/1 mice (Curd's Caviary, Downey, California). Of 500 mice from this colony examined over a two-year period, 320 were infected with an average of 35 worms per mouse, varying from a single 12-in. worm to one or two thousand extremely small ones (demonstrating a ‘crowding effect’). Among more than 12,000 worms recovered, approximately 5 per cent showed one of the following malformations or growth disturbances : (1) Partial twinning (Fig. 1A) : forked posterior strobila ; (2) lateral branching (Fig. 1B) : new tissue outgrowth with varying degrees of differentiation ; (3) dedifferentiation (Fig. 1D) : groups of segments appearing as undifferentiated, vacuolated granular regions ; (4) segment reversal : reversal of normal antero-posterior sequence of proglottides (Fig. 1B) ; (5) combination : dedifferentiation plus branch outgrowth (Fig. 1C ; branch formation with segment reversal (Fig. 1B) ; multiple branching (Fig. 1E).

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Foster, W. D., J. Parasitol., 2, 7 (1915).

  2. 2

    Faust, E. C., China Med. (Miss.) J., 39, 800 (1925).

  3. 3

    Clapham, P. A., J. Helminth., 17, 163 (1939).

  4. 4

    Kuntz, R. E., Proc. Helminth. Soc. Wash., 15, 73 (1948).

  5. 5

    Dollfus, R. P., Ann. Parasit. Hum. Comp., 26, 274 (1951).

  6. 6

    Cram, E. B., J. Parasitol., 14, 54 (1927).

  7. 7

    Dobrovolny, C. G., and Dobrovolny, M. P., Trans. Amer. Microscop. Soc., 54, 22 (1935).

Download references

Author information

Author notes

  1. DONALD HEYNEMAN: On special leave of absence as Head, Department of Parasitology, United States Naval Medical Research Unit No. 3, c/o American Embassy, Cairo.


  1. Department of Zoology, University of California, Los Angeles, California



  1. Search for DONALD HEYNEMAN in:

About this article

Publication history

Issue Date



Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.